#include <bits/stdc++.h>
using namespace std;
int a[10001];
int main() {
  int n, m, k, i, ans = 100000;
  long long temp;
  scanf("%d%d%d", &n, &m, &k);
  for (i = 1; i <= n; i++) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  for (i = 1; i <= n; i += 2) ans = min(ans, a[i]);
  temp = n / 2 + 1;
  temp = m / temp;
  if (temp * k < ans) ans = temp * k;
  printf("%d\n", ans);
  return 0;
}
