#include <bits/stdc++.h>
using namespace std;
void solve();
int main() {
  int t = 1;
  while (t--) solve();
}
long long n, m, k;
long long a[100500];
void solve() {
  cin >> n >> m >> k;
  for (long long i = 0; i < n; i++) cin >> a[i];
  if (n == 1) {
    cout << min(a[0], m * k);
    return;
  }
  if (n % 2 == 0) {
    cout << "0";
    return;
  }
  long long z = n - 1;
  z /= 2;
  long long mn = 0;
  for (long long i = 0; i < n; i++)
    if (i % 2 == 0 && a[i] < a[mn]) mn = i;
  if (m <= z) {
    cout << "0";
    return;
  }
  cout << min(a[mn], (m / (z + 1)) * k);
}
