#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    
    int s1 = b + c + d;
    int s2 = a + c + d;
    int s3 = a + b + d;
    int s4 = a + b + c;
    int parni = 0;
    
    if(s1 % 2 == 0) {
        parni += 1;
    }
    if(s2 % 2 == 0) {
        parni += 1;
    }
    if(s3 % 2 == 0) {
        parni += 1;
    }
    if(s4 % 2 == 0) {
        parni += 1;
    }
    if(parni == 1) {
        cout << "+" << endl;
    }
    else if(parni == 0) {
        cout << "-" << endl;
    }
    else {
        cout << "?" << endl;
    }
    return 0;
}