#include <bits/stdc++.h> using namespace std; typedef long long ll; const int maxn = 1e6 + 10; pair<int,int> offer[maxn]; int main(){ ios_base::sync_with_stdio(false); int n, m, o; cin >> n >> m >> o; multiset<pair<int,int> > room; for (int i = 0; i < n; i++){ int p, c; cin >> p >> c; room.insert({c, p}); } for (int i = 0; i < m; i++){ int v, d; cin >> v >> d; offer[i] = {v, d}; } sort(offer, offer + m); reverse(offer, offer + m); vector<int> vals; for (int i = 0; i < m; i++){ auto it = room.lower_bound({offer[i].second, 0}); if (it == room.end()) continue; vals.push_back(offer[i].first - it->second); room.erase(it); } sort(vals.rbegin(), vals.rend()); ll sum = 0; for (int i = 0; i < min((int)vals.size(), o); i++) sum += vals[i]; cout << sum << '\n'; }