#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int ans = 0;
int maxn[1010];
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= m; ++i) maxn[i] = k;
  for (int i = 0; i < n; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    maxn[x] = min(maxn[x], y);
  }
  for (int i = 1; i <= m; ++i) ans += maxn[i];
  printf("%d\n", min(k, ans));
  return 0;
}
