#include <bits/stdc++.h>
using namespace std;
int n, m, k, a[111111];
int main() {
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  for (int i = 0; i < n; i++) cin >> a[i];
  int maxans = (int)2e9;
  for (int i = 0; i < n; i += 2)
    if (a[i] < maxans) maxans = a[i];
  cout << min((long long)maxans, ((long long)m / ((n + 1) / 2)) * k) << endl;
  return 0;
}
