#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 20;
int arr[N];
int main() {
  int n, m, k, mn = 1e5 + 20;
  cin >> n >> m >> k;
  for (int i = 0; i < n; i++) cin >> arr[i];
  for (int i = 0; i < n; i += 2) mn = min(mn, arr[i]);
  if (n % 2 == 0) return cout << "0", 0;
  int x = n / 2 + 1;
  int q = m / x;
  cout << min(1ll * q * k, 1ll * mn);
  return 0;
}
