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