#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0, m = 0, k = 0, c[1000] = {-1}, r = 0, ci = 0, ans = 0;
  cin >> n >> m >> k;
  for (int i = 0; i < m; i++) c[i] = -1;
  for (int i = 0; i < n; i++) {
    cin >> r >> ci;
    r--;
    if (c[r] == -1)
      c[r] = ci;
    else
      c[r] = min(c[r], ci);
  }
  for (int i = 0; i < m; i++) {
    if (c[i]) {
      ans += min(c[i], k);
      k -= min(c[i], k);
    }
  }
  cout << ans;
  return 0;
}
