#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll t,n,m,x,y;

int main(){
    ios::sync_with_stdio(0);
    cin>>t;
    while(t--){
        cin>>n>>m>>x>>y;
        ll Min = min(x-1,min(m-y,n-1));
        ll temp = n - 2 + abs(x - y);
        if(x==y){
            temp++;
        }
        temp /= 2;
        Min = min(Min,temp);
        cout<<Min*Min<<'\n';
    }
    return 0;
}