Selected Hackathons, Competitions, Etc.
Newsletter Sent Monday, December 5, 2022
MIT Quantum Computing Hackathon
Jan 27th-29th 2023 (Register by Jan 7th)
MIT iQuHACK 2023 is a quantum computing hackathon hosted by MIT iQuISE on January 27-29th, 2023. iQuHACK 2023 will be a hybrid event with both in-person and virtual participation open to everyone, including students and professionals from across the world. Quantum Computing challenges, talks, and prizes will be provided by our diverse panel of sponsors, including IonQ, Microsoft, Agnostiq, Quantinuum, QuEra, Quantum Machines, qBraid, IBM, HRL, Atom Computing, Unitary Fund, MIT CQE, MIT RLE, and MIT EECS. MIT iQuHACK 2023 is open to everyone, regardless of experience, and is free to attend.
Newsletter Sent Monday, November 7, 2022
On November 12-13 at the Bok Center – Hack Web3. It’s open to complete beginners, and is students-only (no pro hackers allowed)! Support will be available from world-leading experts throughout! https://forms.gle/jU5LTLv2XFF8583F8
Newsletter Sent Monday, October 17, 2022
November-December DevPost Hackathons
NEAR MetaBUILD III Hackathon by Near Protocol
PRIZES: $1,000,000 in prizes
DEADLINE: Nov 21, 2022 @ 5:00pm EST
JOIN THE HACKATHON: https://bit.ly/nearbuild3u
AWS Data Exchange for APIs Challenge by Amazon
PRIZES: $35,000 in prizes
DEADLINE: Nov 21, 2022 @ 5:00pm EST
JOIN THE HACKATHON: https://bit.ly/adx4apisu
XDC DeFi Hackathon by XDC Network
PRIZES: $50,750 in prizes
DEADLINE: Dec 19, 2022 @ 5:00pm EST
JOIN THE HACKATHON: https://bit.ly/xdcnetworku
Newsletter Sent Monday, September 26, 2022
October DevPost Hackathon
AWS Health AI Hackathon by Amazon
PRIZES: $48,000 in prizes
DEADLINE: Oct 14, 2022 @ 5:00pm PDT
JOIN THE HACKATHON: https://bit.ly/awshealthu
TechTogether Boston Hackathon
TechTogether's Boston Chapter is hosting our city's first in-person hackathon in two years for people of marginalized genders of all ages. The event will take place October 29-30th in the George Sherman Union at Boston University. Register
Newsletter Sent Monday, August 29, 2022
September DevPost Hackathons
Build the Galaxy's Best Super App by Rapyd
PRIZES: $119,000 in prizes
DEADLINE: September 15 at 5:00pm EDT
JOIN THE HACKATHON: https://bit.ly/htg3uni
HelloSign Go Paperless Hackathon by HelloSign
PRIZES: $30,000 in prizes
DEADLINE: Sep 26, 2022 @ 5:00pm EDT
JOIN THE HACKATHON: https://bit.ly/hellosign22u
Newsletter Sent Thursday, July 21, 2022
August DevPost Hackathons
Polygon BUIDL IT : Summer 2022 by Polygon
PRIZES: $500,000 in prizes
DEADLINE: Aug 1, 2022 @ 5:00pm EDT
THEMES: Blockchain, Gaming, Web
JOIN THE HACKATHON: https://bit.ly/buildit22u
DocuSign Good Code Hackathon by DocuSign
PRIZES: $50,000 in prizes
DEADLINE: August 12 at 2:00pm PDT
THEMES: Mobile, Open Ended, Social Good
JOIN THE HACKATHON: https://bit.ly/goodcodeu
Wix DevCon Hackathon 2022 by Wix
PRIZES: $30,688 in prizes
DEADLINE: August 15 at 5:00pm EDT
THEMES: Gaming, Web
JOIN THE HACKATHON: https://bit.ly/devcon22u
Chirp Developer Challenge by Twitter
PRIZES: $520,600 in prizes
DEADLINE: Aug 19, 2022 @ 5:00pm EDT
THEMES: Social Good, Mobile, Web
JOIN THE HACKATHON: https://bit.ly/chirpchallengeu
Ripple CBDC Innovate by Ripple
PRIZES: $47,000 in prizes
DEADLINE: Aug 25, 2022 @ 2:00pm PDT
THEMES: Blockchain, Fintech, Social Good
JOIN THE HACKATHON: https://bit.ly/cbdc22u
Amazon Sustainability Data Initiative Global Hackathon by Amazon
PRIZES: $100,000 in prizes
DEADLINE: August 30 at 5:00pm EDT
THEMES: Social Good, Beginner Friendly, Open Ended
JOIN THE HACKATHON: https://bit.ly/asdi22u
Newsletter Sent Tuesday, June 28, 2022
Algo Crypto Trading Challenge 2022 (Global)
Algo Crypto Trading Challenge 2022 (Global) is hosted by Algo Challenge Association (ACA). This Challenge is a global and public algorithmic trading competition focus on Crypto currencies. Our aim is to identify and nurture algo talents and advance development of Fintech industry. University students can take this opportunity to enrich their educational experience in algo-trading and to acquire the skill set necessary for this fast-growing market segment.
- Website: https://algochallenge.org/crypto2022/index.html
- Registration Link: https://algochallenge.org/crypto2022/index.html#register
Newsletter Sent Tuesday, June 22, 2022
New DevPost Hackathons
Mixed Reality Dev Days 2022 by Microsoft
Participate in Microsoft's Mixed Reality Dev Days and build a new mixed reality project using MRTK 3, StereoKit, or Babylon.js.
PRIZES: $17,500 in prizes
DEADLINE: July 08 at 5:00pm PDT
THEMES: AR/VR, Beginner Friendly
JOIN THE HACKATHON: https://bit.ly/msdevdaysu
Polkadot Hackathon: North America Edition by AngelHack
Bringing the cutting edge of blockchain to your region
PRIZES: $583,000 in prizes
DEADLINE: July 11 at 12:00am PDT
THEMES: Blockchain, Beginner Friendly, Fintech
JOIN THE HACKATHON: https://bit.ly/polkadotnau
Azure Innovation Challenge by Microsoft (US ONLY)
Deploy and Manage APIs, operations, policies and other artifacts at scale in Azure API Management
Eligibility Note: Participants must all be legal residents of the fifty United States (including the District of Columbia)
PRIZES: $11,000 in prizes
DEADLINE: July 11 at 5:00pm EDT
THEMES: Machine Learning/AI
JOIN THE HACKATHON: https://bit.ly/azureinnovationu
2022 SnapAR Global Lensathon by Snap Inc.
Build engaging AR experiences using Lens Studio powered by Snap
PRIZES: $140,000 in prizes
DEADLINE: July 13 at 5:00pm PDT
THEMES: AR/VR, Beginner Friendly, Open Ended
JOIN THE HACKATHON: https://bit.ly/lensathonu
Build the Galaxy's Best Payment App for Space Tourism by Rapyd
Rapyd's Million Dollar – Greatest Fintech Developer Series
PRIZES: $143,000 in prizes
DEADLINE: July 21 at 5:00pm EDT
THEMES: E-commerce/Retail, Enterprise, Fintech
JOIN THE HACKATHON: https://bit.ly/rapydhtg2u
XDC dApp Summer Hackathon by XDC Network
If you can imagine it, you can Build it on XDC. Build a dApp this summer on XDC Network
PRIZES: $51,750 in prizes
DEADLINE: Jul 25, 2022 @ 5:00pm EDT
THEMES: Fintech, IoT, Blockchain
JOIN THE HACKATHON: https://bit.ly/xdcsummeru
Newsletter Sent Monday, May 30, 2022
ZPrize competition
ZPrize is an industry-wide competition, modeled after the XPrize, to accelerate zero-knowledge cryptography. We have over 32 leading zero-knowledge technology companies contributing to this effort donating $7 million in cash prizes and tokens. Key partners and sponsors to ZPrize include Aleo, Ethereum Foundation, Matter Labs, and AMD-Xilinx.
The application submission date deadline is on 6/10/2022. Each of the 10 competitions will begin on 06/10/2022 and will run throughout the summer.
Newsletter Sent Monday, May 16, 2022
June DevPost Hackathons
Build the Galaxy's Best Checkout by Rapyd
Rapyd's Million Dollar – Greatest Fintech Developer Series
PRIZES: $250,000 in prizes
DEADLINE: May 26, 2022 @ 5:00pm EDT
THEMES: E-commerce/Retail, Enterprise, Fintech
JOIN THE HACKATHON: https://bit.ly/hackthegalaxyu
aelf Web3.0 Hackathon - Legend X by Aelf
Build a fully-functioning C# application on aelf to win over $500,000 in prizes!
PRIZES: $525,000 in prizes
DEADLINE: Jun 1, 2022 @ 10:00pm SGT
THEMES: Blockchain, Web, Gaming
JOIN THE HACKATHON: https://bit.ly/aelf33u
monday.com climate change app challenge by Monday
Build an app for a greener tomorrow
PRIZES: $160,000 in prizes
DEADLINE: Jun 27, 2022 @ 5:00pm EDT
THEMES: Productivity, Social Good
JOIN THE HACKATHON: https://bit.ly/mondayclimateu
TRON Grand Hackathon 2022 by Tron
Accelerate the Future
PRIZES: $1,000,000 in prizes
DEADLINE: July 25 at 5:00pm EDT
THEMES: Blockchain, Open Ended, Web
JOIN THE HACKATHON: https://bit.ly/trongrandu
Newsletter Sent Monday, April 25, 2022
May DevPost Hackathons
Web3 World Championship by Nervos Network
Do you have what it takes to become the next Web3 World Champion? Build a project with Nervos Blockchain in the 100M Dash, Art Attack, and either the Marathon or the Relay Event.
PRIZES: $76,400 in prizes
DEADLINE: May 2, 2022 @ 5:00pm EDT
THEMES: Blockchain, Web
JOIN THE HACKATHON: https://bit.ly/web3champ22u
Go Hack by Google
Learn and build with Go (golang)
PRIZES: $20,000 in prizes
DEADLINE: May 16, 2022 @ 3:00pm PDT
THEMES: Web, Education, Open Ended
JOIN THE HACKATHON: https://bit.ly/gohacku
VeChain Hackathon by VeChain
Taking VeChainThor to the next level with upgraded developer tools and documentation
PRIZES: $90,000 in prizes
DEADLINE: May 16, 2022 @ 5:00pm EDT
THEMES: Blockchain, Fintech, Social Good
JOIN THE HACKATHON: https://bit.ly/vechain22u
Newsletter Sent Monday, April 18, 2022
Harvard i-Lab Venture in Metaverse Hackathon
The Metaverse Hackathon will run from Friday to Sunday, April 22-24. With executives, experts, and investors from Mongo DB, Unity, SoWork, XR Terra, Axon Park, Manta Network, and more! Student teams will build ventures in XR, Blockchain, and other Metaverse-related technology and compete for prizes. Whether you come in with just an idea or already have a venture team. We provide resources for helping you join or create a venture to build it to the next stage. Check out more information on our website.
Please RSVP here to join the hackathon.
Newsletter Sent Monday, March 14, 2022
New DevPost Hackathons
Meter Ethereum Hackathon by Meter.io
Build a dApp on Meter.io for a shot at some of the $100,000 in $MTRG prizes.
PRIZES: $100,000 in prizes
DEADLINE: April 04 at 5:00 pm EDT
THEMES: Blockchain
JOIN THE HACKATHON: https://bit.ly/meter22u
Graph For All Million Dollar Challenge by TigerGraph
Solve real problems with graph technology!
PRIZES: $1,000,000 in prizes
DEADLINE: April 20 at 11:45 pm EDT
THEMES: Machine Learning/AI, Social Good, Health
JOIN THE HACKATHON: https://bit.ly/graphforallu
Oasis Bloom Hackathon by Oasis Foundation
Building the next generation of DApps for Web3 and Beyond.
PRIZES: $200,000 in prizes
DEADLINE: May 2, 2022 @ 5:00pm EDT
THEMES: Blockchain, Gaming, Web
JOIN THE HACKATHON: https://bit.ly/webinfiniteu
Neo Polaris Launchpad by Neo
The newest opportunity for developers to find their way into the Neo ecosystem.
PRIZES: $442,500 in prizes
DEADLINE: May 9, 2022 @ 9:00pm CST
THEMES: Blockchain, Beginner Friendly, Web
JOIN THE HACKATHON: https://bit.ly/neo22u
Newsletter Sent Monday, February 21, 2022
Citadel - Correlation One Fall season regional competitions
February 28 - March 7: East Coast Regional Terminal (virtual)
o Terminal Live is an online game where software engineers and computer scientists (or anyone else interested in coding!) build an algorithm to play a tower defense game in a team-based setting.
April 9th: Boston Regional Datathon (live)
o Datathons are data science competitions that challenge students from the world's best universities to tackle real-world social challenges in topics such as urban traffic, renewable energy, and education. This will be the first in-person event Correlation One will be hosting since the start of the pandemic
Newsletter Sent Monday, January 24, 2022
HopperHacks
This February, Women in Computer Science (WiCS) at Stony Brook University is hosting its 7th annual hackathon, HopperHacks.
HopperHacks is a 24-hour long, social good-focused hackathon to encourage students to make an impact on relevant social issues around the world today, such as mental/physical health, diversity and inclusion, and the environment, all by applying their technical skills. We aim to provide a safe and comfortable environment for undergraduate and graduate students of any background and skill level to participate in. This year we plan to have a hybrid hackathon, allowing participants to show up in person or virtually. Anyone can attend, regardless of major or gender.
Event Details
Date: Saturday, February 12th - Sunday, February 13th
Time: Saturday 9:00 AM EST to Sunday 9:00 AM EST
Location: Stony Brook Union Ballroom & Virtual (Discord)
Participate: https://bit.ly/hh22-register
Volunteer: https://bit.ly/hh22-volunteer
Mentor: https://bit.ly/hh22-mentor
HopperHacks website: hopperhacks.sbuwics.com
MIndsumo Bank/Consulting Projects/Challenges
Top Bank: Project Community Impact - This challenge asks solvers to design the bank’s ESG website and give insights into what they think the layout and focus should look like. Renders, mock websites, and prototypes are highly encouraged!
https://www.mindsumo.com/contests/esgproject
KPMG: Propose a way to keep contract talent engaged in between projects
https://www.mindsumo.com/contests/kpmg-keep-talent-engaged
Student Focused company: Design a digital solution to help students prepare for life after school
https://www.mindsumo.com/contests/studentresources
NOTE: A note/tip if you plan to solve it - the company is not looking for ideas that already exist (e.g. peer to peer). They also do not want students to just elaborate on the problem but actually put in a well thought out idea to solve that problem.
Top Financial Firm: How can an auto/property insurance company better engage with consumers under 35?
https://www.mindsumo.com/contests/engaginginsurance
Newsletter Sent Monday, January 17, 2022
More DevPost February Hackathons
NEAR MetaBUILD Hackathon
A better future requires a better foundation. Build apps capable of taking millions of users on journeys they’ve never been on before. Simple. Scalable. Secure.
PRIZES: $1,000,000 in prizes
DEADLINE: Feb 10, 2022 @ 2:00pm PST
THEMES: Blockchain Beginner Friendly
JOIN THE HACKATHON: https://bit.ly/metabuildu
Flutter Puzzle Hack
Push your creativity to its limits by reimagining this classic puzzle!
PRIZES: $51,046 in prizes
DEADLINE: Feb 28, 2022 @ 2:00pm PST
THEMES: Design Gaming Web
JOIN THE HACKATHON: https://bit.ly/gflutterhacku
Newsletter Sent Monday, January 10, 2022
The MIT Water Innovation Prize is a startup competition focused on water innovation that awards up to $50K in innovation grants annually to student-led teams from across the country and internationally. The Prize started in 2015 and has since awarded $225K across 21 winning teams.
Deadline: January 14th, 2022
Newsletter Sent Monday, December 13, 2021
Datathon@LISH
The Datathon@LISH is a remote two-day data science competition running on the weekend of February 12th, 2022. The event is designed for any US-based university students or affiliates and is organized by the Laboratory for Innovation Science at Harvard.
Register here (at no cost) before December 17th, 2021, to guarantee that you get a participation prize for reaching out baseline score (a t-shirt or $10 Amazon gift card)!
Three reasons to participate:
1. Grow your data science skills
Hone your data science skills by solving our selected prediction problem for social good. Our selected contest problem is sourced from a non-profit working in global development.
2. Win cash prizes, swag, and recognition
Cash prizes and recognition among the Harvard data science community for winners. First Place: $1000, Second Place: $500, Third Place: $250, Top-10 Finish: $50. Participation Prize (t-shirt or $10 gift card) for all that reach baseline in the contest.
3. Help the science of (data) science
To further knowledge on data science, contest code will be collected for a study on data science problem-solving. Participants will also complete two short surveys before and after the contest.
If you have any questions, please reach out to datathonatlish@hbs.edu.
February Devpost Hackathons
Digital HQ Slackathon
Build on Slack for your #DigitalHQ to make your work life simpler, more pleasant and more productive.
PRIZES: $47,000 in prizes
DEADLINE: February 01 at 5:00pm EST
THEMES: Low/No Code, Productivity, Enterprise
JOIN THE HACKATHON: https://bit.ly/slack21u
AWS Disaster Response Hackathon
Improve Disaster Response with Machine Learning
PRIZES: $54,000 in prizes
DEADLINE: February 07 at 5:00pm EST
THEMES: Machine Learning/AI, Social Good
JOIN THE HACKATHON: https://bit.ly/disaster21u
AWS Deep Learning Challenge
Train a deep learning model on new Amazon EC2 DL1 instances powered by Habana Gaudi accelerators.
PRIZES: $150,000 in prizes
DEADLINE: February 14 at 5:00pm EST
THEMES: DevOps, Machine Learning/AI, Open Ended
JOIN THE HACKATHON: https://bit.ly/deeplearningu
Newsletter Sent Monday, November 15, 2021
Hackathon out of Princeton:
Rehack, the first ever collegiate reverse hackathon, is taking place virtually and in-person on November 19-20th, 2021. Our theme this year is accessibility and inclusion, and we are challenging teams to tackle big issues in existing technology, like inaccessibility for individuals with disabilities, or to use technology to solve larger problems, like confronting socioeconomic inequalities. This is a great opportunity to gain hackathon experience and promote your newest entrepreneurial venture. Apply by November 17th!
Newsletter Sent Monday, November 1, 2021
New Devpost Hackathons - Nov - Jan
Hack APAC - “The New Normal is Yours!”
- GOAL: Help define the ‘new normal’ by creating apps to make life safer, easier, or less stressful in the post COVID worldArm-based AWS Graviton2 processors.
- PRIZES: $20,500 in prizes
- ELIGIBILITY NOTE: Specific countries only (see rules)
- DEADLINE: November 15 at 11:45 pm SGT
- THEMES: Enterprise, COVID-19, Social Good
- DETAILS + REGISTRATION: https://bit.ly/hackapacu
Build The World with Dolby.io Hackathon
- GOAL: build spectacular and innovative hybrid audio and video conference experiences
- PRIZES: $25,000 in prizes
- DEADLINE: November 29, 5 PM ET
- THEMES: AR/VR, Communication, Web
- DETAILS + REGISTRATION: https://bit.ly/dolby_21u
Square: Build What’s POS_sible
- GOAL: Build useful solutions with Square’s customer point-of-sale APIs
- PRIZES: $100,000 in prizes
- DEADLINE: Nov 22, 2021 @ 5:00pm EST
- THEMES: E-Commerce/Retail, Fintech
- DETAILS + REGISTRATION: https://bit.ly/squarepos_u
HubSpot Themes Challenge 2021
- GOAL: Build website themes for HubSpot’s marketplace to compete for a Tesla and over $100,000 in cash prizes.
- PRIZES: $155,500 in prizes
- DEADLINE: January 13 at 11:45 pm EST
- THEMES: Enterprise, Design, Web
- DETAILS + REGISTRATION: https://bit.ly/hubspot21u
UiPath Innovation RPA Hackathon 2021
- GOAL: Join the UiPath Innovation RPA Hackathon 2021 to showcase the work you are doing to make a difference in the world through automation that is solving real-world issues!
- PRIZES: $9,300 in prizes
- DEADLINE: November 22 at 5:00 pm EST
- THEMES: Machine Learning/AI, Productivity
- JOIN THE HACKATHON: https://bit.ly/uipathu
5G Edge Computing Challenge with AWS
- GOAL: Build low-latency applications using AWS Wavelength on a 5G network for a chance to win $50,000 in prizes!
- PRIZES: $50,000 in prizes
- DEADLINE: December 13th, 5:00 PM EST
- THEMES: Communication, DevOps, Enterprise
- JOIN THE HACKATHON: https://bit.ly/aws5g21u
Newsletter Sent Monday, September 27, 2021
Devpost Hackathons
AWS Graviton Hackathon
- GOAL: Build or migrate an application to Amazon EC2 instances powered by Arm-based AWS Graviton2 processors.
- PRIZES: $50,000 in prizes
- DEADLINE: Oct 13, 2021 5:00pm EDT
- THEMES: Enterprise, Gaming, Machine Learning/AI
- DETAILS + REGISTRATION: https://bit.ly/awsgravitonU
IGNITION | A Global Solana Hackathon
- GOAL: Build software using Solana Blockchain that fits in one of the below categories. (DeFi, Web3, Gaming, Digital Art/Collectibles).
- PRIZES: $5,000,000 in prizes
- DEADLINE: October 15 11:45PM PDT
- THEMES: Blockchain
- DETAILS + REGISTRATION: https://bit.ly/solana21U
PyTorch Annual Hackathon 2021
- GOAL: Build a project using PyTorch in one of the three categories: PyTorch Responsible AI Development Tools & Libraries, Web and Mobile Applications powered by PyTorch, PyTorch Developer Tools & Libraries
- PRIZES: $39,000 in prizes
- DEADLINE: Nov 3, 2021 5:00pm EDT
- THEMES: Machine Learning/AI
- DETAILS + REGISTRATION: https://bit.ly/PyTorch21U
Newsletter Sent Monday, September 13, 2021
A Healthcare-Focused Hackathon - the Pitt Challenge
Every year Pitt Pharmacy hosts the Pitt Challenge Hackathon, an innovation marathon helping connect healthcare, computer science, engineering, and design (and more!) students to create solutions to healthcare problems. Last year we hosted our hackathon online and with robust participation from around the globe. This year, we are again holding our event online with the support of Major League Hacking, ConnectiveRx, UPMC Enterprises, IQ-Inc and others. This is a great opportunity for students to gain exposure to potential employers and several projects have resulted in seed funding! If this event would be of value to your students, I have included an advertisement to share. It is tentatively scheduled for October 22-23rd. Here is the website we will be updating in the near future for this year’s details: http://pittchallenge.com/.
Newsletter Sent Monday, August 30, 2021
Citadel - Correlation One Fall season regional competitions
These are great learning opportunities for students and I highly encourage freshman and sophomore level students to sign up (competitions are mainly open for undergrads but excited graduate level students are welcome to register)
This Fall, students studying on the East Coast Region are invited for two separate events:
- September 20-27: East Coast Regional Terminal:
- Terminal Live is an online game where software engineers and computer scientists (or anyone else interested in coding!) build an algorithm to play a tower defense game in a team-based setting
- October 25- November 1: East Coast Regional Datathon:
- Datathons are data science competitions that challenge students from the world's best universities to tackle real-world social challenges in topics such as urban traffic, renewable energy, and education.
Newsletter Sent Friday, August 6, 2021
New Devpost Hackathons
Browsers 3000
CHALLENGE: Build applications, websites, browser extensions, libraries, modules, tools or learning materials that bring web3 or P2P to the web we have today.
PRIZES: $38,000 in prizes
DEADLINE: Aug 19, 2021 5:00pm EDT
JOIN THE HACKATHON: https://bit.ly/Browser3000u
DocuSign Good Code Hackathon
CHALLENGE: Develop a web or mobile app using the DocuSign esignature and other APIs to support the Jane Goodall Institute or a non-profit of your choosing.
PRIZES: $50,000 in prizes
DEADLINE: Aug 13, 2021 2:00pm PDT
JOIN THE HACKATHON: https://bit.ly/docusign2021u
Codegeist 2021
CHALLENGE: Build innovative cloud apps using Atlassian’s Forge platform in one of the following categories: Apps for DevOps Teams, Apps for IT, Apps for Business.
PRIZES: $300,000 in prizes
DEADLINE: Sept 13, 2021 5:00pm EDT
JOIN THE HACKATHON: https://bit.ly/Codegeist2021u
Newsletter sent Monday, July 26, 2021
Harvard GSAS Business Club Virtual Pitch Competition
Application deadline August 15. Competition is September 30. Details at this link.
2021 Humana-Mays Healthcare Analytics Case Competition
This competition, taking place from September 8 - November 11, 2021, is aimed at students in master degree programs.