#include <bits/stdc++.h>
int dia[15000];
int main() {
  int n, m, k;
  scanf("%d %d %d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", &dia[i]);
  long long ans;
  if (n % 2 == 1) {
    int need = n / 2 + 1;
    if (m < need)
      ans = 0;
    else {
      ans = dia[0];
      for (int i = 0; i < n; i++)
        if (i % 2 == 0) ans = (ans < dia[i] ? ans : dia[i]);
      long long all = (long long)m / need * k;
      ans = (ans < all ? ans : all);
    }
  } else
    ans = 0;
  printf("%lld\n", ans);
  return 0;
}
