#include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     int n, m, k;     cin >> n >> m >> k;     int result = n - m;     if (k >= abs(result) && k != 0) {       cout <<  ?  <<   n ;     } else {       if (result > 0)         cout <<  + n ;       else if (result < 0)         cout <<  - n ;       else if (result == 0)         cout <<  0 n ;     }     return 0;   }   