import std.stdio, std.conv, std.string, std.bigint;
import std.math, std.random, std.datetime;
import std.array, std.range, std.algorithm, std.container;
string read(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }

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