{"raw_statement":[{"iden":"problem statement","content":"You are given a string $S$ consisting of `<`, `=`, and `>`.  \nDetermine whether $S$ is a **bidirectional arrow** string.  \nA string $S$ is a bidirectional arrow string if and only if there is a positive integer $k$ such that $S$ is a concatenation of one `<`, $k$ `=`s, and one `>`, in this order, with a length of $(k+2)$."},{"iden":"constraints","content":"*   $S$ is a string of length between $3$ and $100$, inclusive, consisting of `<`, `=`, and `>`."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$S$"},{"iden":"sample input 1","content":"<====>"},{"iden":"sample output 1","content":"Yes\n\n`<====>` is a concatenation of one `<`, four `=`s, and one `>`, in this order, so it is a bidirectional arrow string.  \nHence, print `Yes`."},{"iden":"sample input 2","content":"\\==>"},{"iden":"sample output 2","content":"No\n\n`==>` does not meet the condition for a bidirectional arrow string.  \nHence, print `No`."},{"iden":"sample input 3","content":"<>>"},{"iden":"sample output 3","content":"No"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}