Starlight: List of Problems

Over 20,000 problems available. AMC 8/10/12 and AIME problems from 2010-2023; USAJMO/USAMO problems from 2002-2023 available. USACO problems from 2014 to 2023 (all divisions). Codeforces, AtCoder, DMOJ problems are added daily around 04:00 AM UTC, which may cause disruptions.

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AMC 8: [year] AMC 8 Problem #, Ex: 2013 AMC 8 Problem 1
AMC 10: [year] AMC 10A Problem # OR [year] AMC 10B Problem #, Ex: 2015 AMC 10A Problem 16
AMC 12: [year] AMC 12A Problem # OR [year] AMC 12B Problem #, Ex: 2021 AMC 12B Problem 25
AIME: [year] AIME I Problem # OR [year] AIME II Problem #, Ex: 2013 AIME I Problem 8
USAJMO/USAMO: [year] USAJMO/USAMO Problem #, Ex: 2023 USAJMO Problem 1
Codeforces: Codeforces [contest id (e.g. 101)][problem id (e.g. A, B, C)]: [Codeforces problem name], Ex: Codeforces 1336F: Journey
AtCoder: AtCoder [contest id (e.g. ABC314, ARC164, ZONE2021)]: [problem id (A, B, C)]. [Problem name], Ex: AtCoder ZONE2021: E. Sneaking
DMOJ: DMOJ [contest name (if applicable)] [problem number (e.g. P1)] - [Problem name], Ex: DMOJ Yet Another Contest 3 P1 - Shell Swap Scam
USACO: [year] [contest month (e.g. January, US Open)], [division (e.g. Gold)]: [Problem name], Ex: USACO 2023 US Open Contest, Bronze: Rotate and Shift

ID	Problem Name (click to add insights/hints, view summary of insights/hints and similar problems)
3551	Codeforces 835D: Palindromic characteristics
3550	Codeforces 835C: Star sky
3549	Codeforces 835B: The number on the board
3548	Codeforces 835A: Key races
3547	Codeforces 834B: The Festive Evening
3546	Codeforces 834A: The Useless Toy
3545	Codeforces 833E: Caramel Clouds
3544	Codeforces 833D: Red-Black Cobweb
3543	Codeforces 833C: Ever-Hungry Krakozyabra
3542	Codeforces 833B: The Bakery
3541	Codeforces 833A: The Meaningless Game
3540	Codeforces 832E: Vasya and Shifts
3539	Codeforces 832D: Misha, Grisha and Underground
3538	Codeforces 832C: Strange Radiation
3537	Codeforces 832B: Petya and Exam
3536	Codeforces 832A: Sasha and Sticks
3535	Codeforces 831C: Jury Marks
3534	Codeforces 831B: Keyboard Layouts
3533	Codeforces 831A: Unimodal Array
3532	Codeforces 830E: Perpetual Motion Machine
3531	Codeforces 830D: Singer House
3530	Codeforces 830C: Bamboo Partition
3529	Codeforces 830B: Cards Sorting
3528	Codeforces 830A: Office Keys
3527	Codeforces 828B: Black Square
3526	Codeforces 828A: Restaurant Tables
3525	Codeforces 827F: Dirty Arkady's Kitchen
3524	Codeforces 827E: Rusty String
3523	Codeforces 827D: Best Edge Weight
3522	Codeforces 827C: DNA Evolution
3521	Codeforces 827B: High Load
3520	Codeforces 827A: String Reconstruction
3519	Codeforces 825G: Tree Queries
3518	Codeforces 825F: String Compression
3517	Codeforces 825E: Minimal Labels
3516	Codeforces 825D: Suitable Replacement
3515	Codeforces 825C: Multi-judge Solving
3514	Codeforces 825B: Five-In-a-Row
3513	Codeforces 825A: Binary Protocol
3512	Codeforces 822F: Madness
3511	Codeforces 822E: Liar
3510	Codeforces 822D: My pretty girl Noora
3509	Codeforces 822C: Hacker, pack your bags!
3508	Codeforces 822B: Crossword solving
3507	Codeforces 822A: I'm bored with life
3506	Codeforces 821E: Okabe and El Psy Kongroo
3505	Codeforces 821D: Okabe and City
3504	Codeforces 821C: Okabe and Boxes
3503	Codeforces 821B: Okabe and Banana Trees
3502	Codeforces 821A: Okabe and Future Gadget Laboratory

Problem Name (click to add insights/hints, view summary of insights/hints and similar problems)

3551

Codeforces 835D: Palindromic characteristics

3550

Codeforces 835C: Star sky

3549

Codeforces 835B: The number on the board

3548

Codeforces 835A: Key races

3547

Codeforces 834B: The Festive Evening

3546