{"problem":{"name":"A Unique Letter","description":{"content":"You are given a string $S$ of length $3$.   Print a character that occurs only once in $S$.   If there is no such character, print `-1` instead.","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc260_a"},"statements":[{"statement_type":"Markdown","content":"You are given a string $S$ of length $3$.  \nPrint a character that occurs only once in $S$.  \nIf there is no such character, print `-1` instead.\n\n## Constraints\n\n*   $S$ is a string of length $3$ consisting of lowercase English letters.\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":"abc260_a","tags":[],"sample_group":[["pop","o\n\n`o` occurs only once in `pop`."],["abc","a\n\n`a`, `b`, and `c` occur once each in `abc`, so you may print any of them."],["xxx","\\-1\n\nNo character occurs only once in `xxx`."]],"created_at":"2026-03-03 11:01:14"}}