#include<bits/stdc++.h>
using namespace std;
#define ll long long

int t,n,m,a,b;

inline int rd()
{
    int x=0;char ch=getchar();
    for (;ch<'0'||ch>'9';ch=getchar());
    for (;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0';
    return x;
}

int main()
{
    t=rd();
    while (t--)
    {
        n=rd();m=rd();a=rd();b=rd();
        int ans=min(a-1,m-b);
        ans=min(ans,n-1);
        if (a==b) ans=min(ans,(n-1)/2);
        else
        {
            int hh=n-1+abs(a-b);
            if (hh%2==1) ans=min(ans,hh/2);
            else ans=min(ans,hh/2-1);
        }
        printf("%lld\n",(ll)ans*ans);
    }
    return 0;
}