#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k, a, b;
  cin >> n >> m >> k;
  int no[m];
  for (int i = 0; i < m; i++) no[i] = 10000000;
  for (int i = 0; i < n; i++) {
    cin >> a >> b;
    if (b < no[a - 1]) no[a - 1] = b;
  }
  int res = 0;
  for (int i = 0; i < m; i++) {
    if (no[i] != 10000000) res += no[i];
  }
  res = (k > res ? res : k);
  cout << res << "\n";
  return 0;
}
