func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int a, b, c, n;     cin >> a >> b >> c >> n;     int d = n - (a + b - c);     if ((a - c) >= 0 && (b - c) >= 0 && c >= 0 && d > 0) {       cout << d << endl;     } else       cout << -1 << endl;     return 0;   }   