#include <bits/stdc++.h>
using namespace std;
int i, j, n, k, m, y, a, c;
vector<int> x(1001, 9999999);
int main() {
  cin >> n >> m >> c;
  for (i = 1; i <= n; i++) {
    cin >> k >> j;
    x[k] = min(x[k], j);
  }
  j = 0;
  for (i = 1; i <= m; i++) j += x[i];
  if (j > c) j = c;
  cout << j << endl;
}
