import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
import std.typecons;

void main() {
    auto a = read.to!int;
    auto b = read.to!int;
    if (a + b == 15) writeln("+");
    else if (a * b == 15) writeln("*");
    else writeln("x");
}

string read() {
    static string[] ss;
    while (!ss.length) ss = readln.chomp.split;
    auto res = ss[0];
    ss.popFront;
    return res;
}