{"raw_statement":[{"iden":"problem statement","content":"Having learned the multiplication table, Takahashi can multiply two integers between $1$ and $9$ (inclusive) together. He cannot do any other calculation.\nGiven are two integers $A$ and $B$.\nIf Takahashi can calculate $A \\times B$, print the result; if he cannot, print `-1` instead."},{"iden":"constraints","content":"*   $1 \\leq A \\leq 20$\n*   $1 \\leq B \\leq 20$\n*   All values in input are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$A$ $B$"},{"iden":"sample input 1","content":"2 5"},{"iden":"sample output 1","content":"10\n\n$2 \\times 5 = 10$."},{"iden":"sample input 2","content":"5 10"},{"iden":"sample output 2","content":"\\-1\n\n$5\\times 10 = 50$, but Takahashi cannot do this calculation, so print `-1` instead."},{"iden":"sample input 3","content":"9 9"},{"iden":"sample output 3","content":"81"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}