#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, k, a, mi = 1000000;
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  if (n / 2 + 1 > m) {
    cout << 0;
    return 0;
  }
  for (int i = 0; i < n; i += 2) {
    cin >> a;
    if (a < mi) mi = a;
    cin >> a;
  }
  if (n == 1) {
    cout << min(mi, k * m);
    return 0;
  }
  cout << min(k * (m / (n / 2 + 1)), mi);
  return 0;
}
