#include <iostream>


using namespace std;

int main()
{
   int a, b, c, d;
   cin >> a >> b >> c >> d;
   int bez_a = b + c + d;
   int bez_b = a + c + d;
   int bez_c = a + b + d;
   int bez_d = a + b + c;
   int temporary_plus = 0;
   if(bez_a % 2 == 0)
   {
       temporary_plus++;
   }
    if(bez_b % 2 == 0)
   {
       temporary_plus++;
   }
    if(bez_c % 2 == 0)
   {
       temporary_plus++;
   }
    if(bez_d % 2 == 0)
   {
       temporary_plus++;
   }
   if(temporary_plus == 0)
   {
       cout << "-" << endl;
   }
   else if(temporary_plus == 1)
   {
       cout << "+" << endl;
   }
   else
   {
       cout << "?" << endl;
    }
   return 0;
}