{"raw_statement":[{"iden":"problem statement","content":"You are given a string $S$ consisting of lowercase English letters.  \nIf `a` appears in $S$, print the last index at which it appears; otherwise, print $-1$. (The index starts at $1$.)"},{"iden":"constraints","content":"*   $S$ is a string of length between $1$ and $100$ (inclusive) consisting of lowercase English letters."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$S$"},{"iden":"sample input 1","content":"abcdaxayz"},{"iden":"sample output 1","content":"7\n\n`a` appears three times in $S$. The last occurrence is at index $7$, so you should print $7$."},{"iden":"sample input 2","content":"bcbbbz"},{"iden":"sample output 2","content":"\\-1\n\n`a` does not appear in $S$, so you should print $-1$."},{"iden":"sample input 3","content":"aaaaa"},{"iden":"sample output 3","content":"5"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}