#include <bits/stdc++.h>
using namespace std;
const int N = 110, MOD = 1e9 + 7;
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<ll> VLL;
typedef queue<PII> QPII;
typedef stack<int> SI;
typedef vector<PII> VPII;
typedef deque<int> DPII;
typedef queue<int> QI;
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
int n, m, x, y;
PII a[N], b[N], c[N], d[N];

int main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t;
    cin >> t;
    while(t--){
        cin >> n >> m >> x >> 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;
            }
            sort(a, a + x);
            sort(b, b + y);
            int idxc=0,idxd=0;
            c[idxc++]=a[0];
            d[idxd++]=b[0];
            for (int i = 1; i < x; i++){
                if(c[idxc-1].second>=a[i].first){
                    c[idxc-1].second = max(c[idxc-1].second,a[i].second);
                }
                else {
                    c[idxc++] = a[i];
                }
            }
            for (int i = 1; i < y; i++){
                if(d[idxd-1].second>=b[i].first){
                    d[idxd-1].second = max(d[idxd-1].second,b[i].second);
                }
                else {
                    d[idxd++] = b[i];
                }
            }
            ll res =0;
            for(int i=0;i<idxc;i++){
                for(int j=0;j<idxd;j++){
                    if(c[i].second>=d[j].first&&c[i].first<=d[j].second){
                        int st = max(c[i].first,d[j].first);
                        int ed = min(c[i].second,d[j].second);
                        if(ed-st+1>=m)
                        res += ed-m-st+2;
                    }
                    else {
                        break;
                    }
                }
            }
            cout<<res<<'\n';

    }
    
    return 0;
}