#include <bits/stdc++.h>
using namespace std;
int main() {
  long long i, n, m, k, a[10001];
  cin >> n >> m >> k;
  for (i = 0; i < n; i++) cin >> a[i];
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  if (m / (n / 2 + 1) == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long ans = (m / (n / 2 + 1)) * k;
  for (i = 0; i < n; i += 2) ans = min(a[i], ans);
  cout << ans << endl;
  return 0;
}
