{"problem":{"name":"YYMM or MMYY","description":{"content":"You have a digit sequence $S$ of length $4$. You are wondering which of the following formats $S$ is in: *   YYMM format: the last two digits of the year and the two-digit representation of the month","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc126_b"},"statements":[{"statement_type":"Markdown","content":"You have a digit sequence $S$ of length $4$. You are wondering which of the following formats $S$ is in:\n\n*   YYMM format: the last two digits of the year and the two-digit representation of the month (example: `01` for January), concatenated in this order\n*   MMYY format: the two-digit representation of the month and the last two digits of the year, concatenated in this order\n\nIf $S$ is valid in only YYMM format, print `YYMM`; if $S$ is valid in only MMYY format, print `MMYY`; if $S$ is valid in both formats, print `AMBIGUOUS`; if $S$ is valid in neither format, print `NA`.\n\n## Constraints\n\n*   $S$ is a digit sequence of length $4$.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$S$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc126_b","tags":[],"sample_group":[["1905","YYMM\n\nMay $XX19$ is a valid date, but $19$ is not valid as a month. Thus, this string is only valid in YYMM format."],["0112","AMBIGUOUS\n\nBoth December $XX01$ and January $XX12$ are valid dates. Thus, this string is valid in both formats."],["1700","NA\n\nNeither $0$ nor $17$ is valid as a month. Thus, this string is valid in neither format."]],"created_at":"2026-03-03 11:01:14"}}