{"raw_statement":[{"iden":"problem statement","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."},{"iden":"constraints","content":"*   $S$ is a string of length $3$ consisting of lowercase English letters."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$S$"},{"iden":"sample input 1","content":"pop"},{"iden":"sample output 1","content":"o\n\n`o` occurs only once in `pop`."},{"iden":"sample input 2","content":"abc"},{"iden":"sample output 2","content":"a\n\n`a`, `b`, and `c` occur once each in `abc`, so you may print any of them."},{"iden":"sample input 3","content":"xxx"},{"iden":"sample output 3","content":"\\-1\n\nNo character occurs only once in `xxx`."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}