#include <bits/stdc++.h>
 
using namespace std;
 
const int MaxN = (int)2e3 + 10;
const int INF = (int)1e9;
const int MOD = 998244353;

void solve() {
	int n, m, x, y;
	scanf("%d%d%d%d", &n, &m, &x, &y);
	int total = (n * m - 1) * (n * m - 2);
	total -= (n - 1) * m * (m - 1);
	total -= (m - 1) * n * (n - 1);
	total -= (x - 1) * (x - 2);
	total -= (y - 1) * (y - 2);
	total -= (n - x) * (n - x - 1);
	total -= (m - y) * (m - y - 1);
	map <int, int> mx, mn;
	for (int i = 1; i <= n + m - 1; ++i) {
		mx[i] = 0;
		mn[i] = INF;
	}
	for (int i = 1; i <= n; ++i) {
		mx[i + 1] = max(mx[i + 1], i);
		mn[i + 1] = min(mn[i + 1], i);
		mx[i + m] = max(mx[i + m], i);
		mn[i + m] = min(mn[i + m], i);
	}
	for (int j = 1; j <= m; ++j) {
		mx[1 + j] = max(mx[1 + j], 1);
		mn[1 + j] = min(mn[1 + j], 1);
		mx[n + j] = max(mx[n + j], n);
		mn[n + j] = min(mn[n + j], n);
	}
	for (int d = 1; d <= n + m - 1; ++d) {
		int a = mn[d], b = mx[d];
		if (a == 0 || b == 0) continue;
		if (d != x + y) {
			total -= (b - a + 1) * (b - a);
		} else {
			total -= (b - x) * (b - x - 1);
			total -= (x - a) * (x - a - 1);
		}
	}
	for (int i = 1 - m; i <= n - 1; ++i) {
		mx[i] = 0;
		mn[i] = INF;
	}
	for (int i = 1; i <= n; ++i) {
		mx[i - 1] = max(mx[i - 1], i);
		mn[i - 1] = min(mn[i - 1], i);
		mx[i - m] = max(mx[i - m], i);
		mn[i - m] = min(mn[i - m], i);
	}
	for (int j = 1; j <= m; ++j) {
		mx[1 - j] = max(mx[1 - j], 1);
		mn[1 - j] = min(mn[1 - j], 1);
		mx[n - j] = max(mx[n - j], n);
		mn[n - j] = min(mn[n - j], n);
	}
	for (int d = 1 - m; d <= n - 1; ++d) {
		int a = mn[d], b = mx[d];
		if (a == 0 || b == 0) continue;
		if (d != x - y) {
			total -= (b - a + 1) * (b - a);
		} else {
			total -= (b - x) * (b - x - 1);
			total -= (x - a) * (x - a - 1);
		}
	}
	cout << total << "\n";
}

int main() {
//	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
	int t;
	scanf("%d", &t);
	while (t --> 0) {
		solve();
	}
	return 0;
}