#include <bits/stdc++.h>
using namespace std;
template <class T>
inline string tostring(T a) {
  ostringstream sout;
  sout << a;
  return sout.str();
}
template <class T>
T gcd(T a, T b) {
  return a == 0 ? b : gcd(b % a, a);
}
template <class T>
void operator>>(istream &a, vector<T> &b) {
  for (int i = 0; i < b.size(); i++) a >> b[i];
}
int main() {
  int a[1001];
  int m, n, k;
  memset(a, -1, sizeof(a));
  cin >> m >> n >> k;
  int p, q;
  for (int i = 0; i < m; i++) {
    cin >> p >> q;
    if (a[p] == -1) {
      a[p] = q;
    } else
      a[p] = min(a[p], q);
  }
  int sum = 0;
  for (int i = 1; i <= m; i++) {
    if (a[i] != -1) sum += a[i];
  }
  cout << min(sum, k) << endl;
}
