#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
inline int my_getchar_unlocked(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread_unlocked(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline int rd_int(void){
  int x;
  rd(x);
  return x;
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite_unlocked(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar_unlocked(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar_unlocked(a);
}
inline void wt_L(long long x){
  int s=0;
  int m=0;
  char f[20];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar_unlocked('-');
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
int up[40001];
int dw[40001];
int main(){
  int Lj4PdHRW;
  int X1;
  int Y1;
  int X2;
  int Y2;
  long long res;
  int KL2GvlyY = rd_int();
  for(Lj4PdHRW=(0);Lj4PdHRW<(KL2GvlyY);Lj4PdHRW++){
    int i;
    rd(X1);
    rd(Y1);
    rd(X2);
    rd(Y2);
    {
      auto cTE1_r3A = (20000);
      X1 += cTE1_r3A;
      X2 += cTE1_r3A;
    }
    res = 0;
    Y1 *= -1;
    for(i=(X1);i<(X2);i++){
      if(dw[i] < Y1){
        res += Y1 - dw[i];
        dw[i] = Y1;
      }
    }
    for(i=(X1);i<(X2);i++){
      if(up[i] < Y2){
        res += Y2 - up[i];
        up[i] = Y2;
      }
    }
    wt_L(res);
    wt_L('\n');
  }
  return 0;
}
// cLay varsion 20200509-1

// --- original code ---
// int up[40001], dw[40001];
// {
//   int X1, Y1, X2, Y2;
//   ll res;
// 
//   REP(rd_int()){
//     rd(X1, Y1, X2, Y2);
//     (X1,X2) += 20000;
//     res = 0;
//     Y1 *= -1;
//     rep(i,X1,X2) if(dw[i] < Y1) res += Y1 - dw[i], dw[i] = Y1;
//     rep(i,X1,X2) if(up[i] < Y2) res += Y2 - up[i], up[i] = Y2;
//     wt(res);
//   }
// 
// }