#include <bits/stdc++.h>
using namespace std;
const int N = 1e3 + 7;
int row[N];
int n, m, k;
void init() {
  for (int i = 0; i < m + 1; ++i) {
    row[i] = 1e6 + 7;
  }
}
int main() {
  scanf("%d %d %d", &n, &m, &k);
  init();
  int r, d;
  for (int i = 0; i < n; ++i) {
    scanf("%d %d", &r, &d);
    row[r] = min(row[r], d);
  }
  int ans = 0;
  for (int i = 1; i <= m && k; ++i) {
    int taken = min(k, row[i]);
    ans += taken;
    k -= taken;
  }
  printf("%d", ans);
}
