#include <bits/stdc++.h>
using namespace std;
long long a[100010], minn = 555555555;
int main() {
  long long n, m, k;
  scanf("%lld%lld%lld", &n, &m, &k);
  for (int i = 1; i <= n; i++) {
    scanf("%lld", &a[i]);
    if (i % 2 == 1) minn = min(minn, a[i]);
  }
  if (n % 2 == 0) {
    printf("0");
  } else {
    if (m < (n + 1) / 2) {
      printf("0");
    } else {
      long long ans1 = m / ((n + 1) / 2) * k, ans = min(minn, ans1);
      printf("%lld", ans);
    }
  }
}
