func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     long long n, i, x1, y1, x2, y2;     cin >> x1 >> y1 >> x2 >> y2;     cout << (x2 - x1) * (y2 - y1) + 1 <<   n ;   }   int main() {     std::ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long tt;     cin >> tt;     while (tt--) {       solve();     }     cerr <<   Execution :   << (1.0 * clock()) / CLOCKS_PER_SEC <<  s  n ;     return 0;   }   