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