"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const A = ~~arg[0].split(" ")[0];
    const B = ~~arg[0].split(" ")[1];
    
    if(A + B === 15) {
        console.log("+");
    } else if(A * B === 15) {
        console.log("*");
    } else {
        console.log("x");
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));