#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, m, k;
  cin >> n >> m >> k;
  long long int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  if (n % 2 == 0) {
    cout << "0";
    return 0;
  }
  long long int b = n / 2 + 1;
  long long int b1 = m / b;
  if (b1 == 0) {
    cout << "0";
    return 0;
  }
  long long int ans = b1 * k;
  for (int i = 0; i < n; i = i + 2) {
    if (a[i] < ans) ans = a[i];
  }
  cout << ans;
}
