#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using PII = pair<int, int>;
void solve() {
	int n, m, x, y;
	cin >> n >> m >> x >> y;
	std::vector<PII> a(x), b(y);
	for(int i = 0; i < x; i++) {
		cin >> a[i].first >> a[i].second;
	}
	for(int i = 0; i < y; i++) {
		cin >> b[i].first >> b[i].second;
	}
	ll sum = 0;
	int i = 0, j = 0;
	while(x > i && y > j) {
		int maxx = max(a[i].first, b[j].first);
		int minn = min(a[i].second, b[j].second);
		if(minn - maxx >= m - 2) {
			sum += (ll)minn - maxx - m + 2;
		}
		i += (a[i].second <= b[j].second);
		j += (a[i].second > b[j].second);
	}
	cout << sum << '\n';
	return;
}
int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	int t = 1;
	cin >> t;
	while(t--) solve();
	return 0;
}