func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize(2)   using namespace std;   inline long long read() {     long long x = 0, w = 1;     char c = getchar();     while (c <  0  || c >  9 ) {       if (c ==  - ) w = -1;       c = getchar();     }     while (c <=  9  && c >=  0 ) {       x = (x << 1) + (x << 3) + c -  0 ;       c = getchar();     }     return w == 1 ? x : -x;   }   const int N = 1e5 + 10;   int a[N], n;   int main() {     int _ = read();     while (_--) {       long long x1 = read(), y1 = read();       long long x2 = read(), y2 = read();       if (x1 == x2 || y1 == y2) {         puts( 1 );         continue;       }       long long ans = (x2 - x1) * (y2 - y1) + 1;       printf( %lld n , ans);     }   }   