#include <bits/stdc++.h>

using i64 = long long;

void solve() {
    int n, m, x, y;
    std::cin >> n >> m >> x >> y;
    
    std::vector<std::pair<int, int>> a(x), b(y);
    int ans = 0;
    for (int i = 0; i < x; i++) {
        int l, r;
        std::cin >> l >> r;
        a[i] = {l, r};
    }
    for (int i = 0; i < y; i++) {
        int l, r;
        std::cin >> l >> r;
        b[i] = {l, r};
    }
    for (int i = 0; i < x; i++) {
        for (int j = 0; j < y; j++) {
            int l = std::max(a[i].first, b[j].first);
            int r = std::min(a[i].second, b[j].second);
            ans += std::max(0, r - l + 1 - m + 1);
        }
    }
    std::cout << ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int t;
    std::cin >> t;
    
    while (t--) {
        solve();
    }
    
    return 0;
}