#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[10001] = {};
  long long n, m, k, mx, kol, count;
  cin >> n >> m >> k;
  mx = 1000000;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (i % 2 == 0 && a[i] < mx) mx = a[i];
  }
  if (n % 2 == 0 || m < n / 2 + 1 || mx == 0) {
    cout << 0 << endl;
    return 0;
  }
  if (mx == 0) {
    cout << 0 << endl;
    return 0;
  }
  count = kol = 0;
  kol = m / (n / 2 + 1);
  if (kol * k >= mx)
    count = mx;
  else
    count = kol * k;
  cout << count << endl;
  return 0;
}
