#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)
    cout << 0 << endl;
  else if (n == 1)
    cout << min(a[0], m * k) << endl;
  else {
    long long maxN = INT_MAX;
    for (int i = 0; i < n; i += 2) maxN = min(maxN, a[i]);
    maxN = min(maxN, (m / (n / 2 + 1) * k));
    cout << maxN << endl;
  }
  return 0;
}
