import std.stdio;

string solve (int a, int b)
{
	if (a * b == 15)
	{
		return "*";
	}
	if (a + b == 15)
	{
		return "+";
	}
	return "x";
}

void main ()
{
	int a, b;
	while (readf (" %s %s", &a, &b) > 0)
	{
		writeln (solve (a, b));
	}
}
