#include <bits/stdc++.h>
using namespace std;
priority_queue<int>p;
void solve() {
	while(!p.empty()) p.pop();
    int n, l, m;
    cin >> n >> m >> l;
 
    vector<pair<int, int>> h(n);
    for (int i = 0; i < n; i++) {
    	int x,y;
        cin >> x >> y;
        h[i] = {x, y - x + 2};
    }
int x[m],u[m];
    for (int i = 0; i < m; i++) {
        cin >> x[i] >> u[i];
        }
 
    int curr = 1, ans = 0; 
    for (int i = 0; i < n; i++) {int j=0;
        while (j<m && x[j]<h[i].first) {p.push(u[j]);j++;}
        while(curr<h[i].second){
        	if(p.empty()){cout<<-1<<endl;return;}
        	curr+=p.top();ans++;p.pop();}}
 
    cout << ans << endl;
}
 
int main() {
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}
 

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4
2 5 50
7 14
30 40
2 2
3 1
3 5
18 2
22 32
4 3 50
4 6
15 18
20 26
34 38
1 2
8 2
10 2
1 4 17
10 14
1 6
1 2
1 2
16 9
1 2 10
5 9
2 3
2 2