#include <bits/stdc++.h>
int a[10005];
int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  if (n % 2 == 0)
    printf("0");
  else {
    for (int i = 0; i < n; i++) scanf("%d", &a[i]);
    int minmin = 1000000001;
    for (int i = 0; i < n; i += 2) {
      if (minmin > a[i]) minmin = a[i];
    }
    long long res = (long long)k * (m / (n / 2 + 1));
    if (res > minmin) res = minmin;
    printf("%d", res);
  }
  return 0;
}
