#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, M, K, R, C, ans = 0;
  cin >> N >> M >> K;
  map<int, int> cont;
  while (N--) {
    cin >> R >> C;
    if (!cont.count(R) || cont[R] > C) cont[R] = C;
  }
  map<int, int>::iterator itr = cont.begin();
  for (; itr != cont.end(); itr++) ans += itr->second;
  (ans <= K) ? cout << ans : cout << K;
  return 0;
}
