{"problem":{"name":"Double Helix","description":{"content":"On the Planet AtCoder, there are four types of bases: `A`, `C`, `G` and `T`. `A` bonds with `T`, and `C` bonds with `G`. You are given a letter $b$ as input, which is `A`, `C`, `G` or `T`. Write a pro","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc122_a"},"statements":[{"statement_type":"Markdown","content":"On the Planet AtCoder, there are four types of bases: `A`, `C`, `G` and `T`. `A` bonds with `T`, and `C` bonds with `G`.\nYou are given a letter $b$ as input, which is `A`, `C`, `G` or `T`. Write a program that prints the letter representing the base that bonds with the base $b$.\n\n## Constraints\n\n*   $b$ is one of the letters `A`, `C`, `G` and `T`.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$b$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc122_a","tags":[],"sample_group":[["A","T"],["G","C"]],"created_at":"2026-03-03 11:01:14"}}