#include <bits/stdc++.h>
long long n, m, k, a[11111], kq;
long long min(long long a, long long b) {
  if (a < b) return a;
  return b;
}
int main() {
  scanf("%lld %lld %lld", &n, &m, &k);
  for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
  if (n % 2 == 0)
    printf("0");
  else {
    kq = a[1];
    for (int i = 3; i <= n; i += 2) kq = min(kq, a[i]);
    kq = min(kq, (m / ((n + 1) / 2)) * k);
    printf("%lld", kq);
  }
}
