#include <stdio.h>

int main()
{
    int a, b, sum, multi;
    scanf("%d%d", &a, &b);
    sum = a + b;
    multi = a * b; //multiplication
    if(sum == 15 ){
        printf("+\n", sum);
    }
    if(multi == 15){
        printf("*\n", multi);
    }
    else{
        printf("x\n");
    }
    
    
    return 0;
}
