#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long a[100000];
int ans = 0;
long long mmin = 1 << 30;
int main() {
  ios_base::sync_with_stdio(0);
  cin >> n >> m >> k;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (i % 2 == 0) mmin = min(mmin, a[i]);
  }
  if (n % 2 == 0) {
    cout << 0;
  } else {
    int cost = m / (n / 2 + 1);
    if (cost == 0) {
      cout << 0;
    } else {
      cout << min(mmin, k * cost);
    }
  }
  return 0;
}
