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Register for CS50x Puzzle Day 2025
CS50x PUZZLE DAY 2025
Solve a packet of problems!
Friday, April 4, 2025 – Monday, April 7, 2025
Register here! See
https://cs50.ly/puzzles
for all details!
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Email
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Your email
Are you sure your email address is correct?
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Yes!
Name
*
Your answer
Country
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Choose
Afghanistan
Åland Islands
Albania
Algeria
American Samoa
Andorra
Angola
Anguilla
Antarctica
Antigua and Barbuda
Argentina
Armenia
Aruba
Australia
Austria
Azerbaijan
Bahamas (the)
Bahrain
Bangladesh
Barbados
Belarus
Belgium
Belize
Benin
Bermuda
Bhutan
Bolivia (Plurinational State of)
Bonaire, Sint Eustatius and Saba
Bosnia and Herzegovina
Botswana
Bouvet Island
Brazil
British Indian Ocean Territory (the)
Brunei Darussalam
Bulgaria
Burkina Faso
Burundi
Cabo Verde
Cambodia
Cameroon
Canada
Cayman Islands (the)
Central African Republic (the)
Chad
Chile
China
Christmas Island
Cocos (Keeling) Islands (the)
Colombia
Comoros (the)
Congo (the Democratic Republic of the)
Congo (the)
Cook Islands (the)
Costa Rica
Côte d'Ivoire
Croatia
Cuba
Curaçao
Cyprus
Czechia
Denmark
Djibouti
Dominica
Dominican Republic (the)
Ecuador
Egypt
El Salvador
Equatorial Guinea
Eritrea
Estonia
Eswatini
Ethiopia
Falkland Islands (the) [Malvinas]
Faroe Islands (the)
Fiji
Finland
France
French Guiana
French Polynesia
French Southern Territories (the)
Gabon
Gambia (the)
Georgia
Germany
Ghana
Gibraltar
Greece
Greenland
Grenada
Guadeloupe
Guam
Guatemala
Guernsey
Guinea
Guinea-Bissau
Guyana
Haiti
Heard Island and McDonald Islands
Holy See (the)
Honduras
Hong Kong
Hungary
Iceland
India
Indonesia
Iran (Islamic Republic of)
Iraq
Ireland
Isle of Man
Israel
Italy
Jamaica
Japan
Jersey
Jordan
Kazakhstan
Kenya
Kiribati
Korea (the Democratic People's Republic of)
Korea (the Republic of)
Kuwait
Kyrgyzstan
Lao People's Democratic Republic (the)
Latvia
Lebanon
Lesotho
Liberia
Libya
Liechtenstein
Lithuania
Luxembourg
Macao
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands (the)
Martinique
Mauritania
Mauritius
Mayotte
Mexico
Micronesia (Federated States of)
Moldova (the Republic of)
Monaco
Mongolia
Montenegro
Montserrat
Morocco
Mozambique
Myanmar
Namibia
Nauru
Nepal
Netherlands (the)
New Caledonia
New Zealand
Nicaragua
Niger (the)
Nigeria
Niue
Norfolk Island
North Macedonia
Northern Mariana Islands (the)
Norway
Oman
Pakistan
Palau
Palestine, State of
Panama
Papua New Guinea
Paraguay
Peru
Philippines (the)
Pitcairn
Poland
Portugal
Puerto Rico
Qatar
Réunion
Romania
Russian Federation (the)
Rwanda
Saint Barthélemy
Saint Helena, Ascension and Tristan da Cunha
Saint Kitts and Nevis
Saint Lucia
Saint Martin (French part)
Saint Pierre and Miquelon
Saint Vincent and the Grenadines
Samoa
San Marino
Sao Tome and Principe
Saudi Arabia
Senegal
Serbia
Seychelles
Sierra Leone
Singapore
Sint Maarten (Dutch part)
Slovakia
Slovenia
Solomon Islands
Somalia
South Africa
South Georgia and the South Sandwich Islands
South Sudan
Spain
Sri Lanka
Sudan (the)
Suriname
Svalbard and Jan Mayen
Sweden
Switzerland
Syrian Arab Republic (the)
Taiwan (Province of China)
Tajikistan
Tanzania, the United Republic of
Thailand
Timor-Leste
Togo
Tokelau
Tonga
Trinidad and Tobago
Tunisia
Turkey
Turkmenistan
Turks and Caicos Islands (the)
Tuvalu
Uganda
Ukraine
United Arab Emirates (the)
United Kingdom of Great Britain and Northern Ireland (the)
United States Minor Outlying Islands (the)
United States of America (the)
Uruguay
Uzbekistan
Vanuatu
Venezuela (Bolivarian Republic of)
Viet Nam
Virgin Islands (British)
Virgin Islands (U.S.)
Wallis and Futuna
Western Sahara*
Yemen
Zambia
Zimbabwe
City/State
Your answer
Gender
Your answer
Age
Your answer
Have you participated in CS50x Puzzle Day before?
Yes, CS50x Puzzle Day 2024
Yes, CS50x Puzzle Day 2023
Yes, CS50x Puzzle Day 2022
Yes, CS50x Puzzle Day 2020 in September 2020
Yes, CS50x Puzzle Day 2020 in April 2020
Yes, CS50x Puzzle Day 2019
Yes, CS50x Puzzle Day 2018
Yes, CS50x Puzzle Day 2017
Yes, CS50x Puzzle Day 2016
No
How did you hear about CS50x Puzzle Day 2025?
Discord
edX
Email
Facebook
Friend
Instagram
LinkedIn
Reddit
Slack
Snapchat
Teacher
Telegram
Threads
TikTok
Twitter/X
YouTube
Other:
Are you looking for teammates?
*
Yes
No
Other:
Are you a teacher hoping to host CS50x Puzzle Day 2025 at your school?
Yes
No
Other:
Clear selection
I understand that, if I have any teammates, they should also register themselves individually via this same form.
*
I understand. I have one or more teammates and will remind them to register!
I understand. I have one or more teammates, and they have registered already.
I understand. But I don't have any teammates
Other:
I understand that submitting my answers to the puzzles will require that I log in with a (free) GitHub account
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If you don't have one already, you can sign up for a (free) GitHub account at
https://github.com/signup
Yes, I understand
Comments, if any
Your answer
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