function Main(input) {

    input = input.split(" ");

    var a = parseInt(input[0], 10);
    var b = parseInt(input[1], 10);

    if (b % a == 0) {
        console.log(a + b);
    } else {
        console.log(b - a);
    }
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));