#include <bits/stdc++.h>
using namespace std;
int a[20000];
int main() {
  int i, n, m, k, tmp;
  long long ans;
  scanf("%d%d%d", &n, &m, &k);
  for (i = 0; i < n; i++) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  tmp = (n + 1) / 2;
  ans = m / tmp;
  ans *= k;
  for (i = 0; i < n; i += 2)
    if (a[i] < ans) ans = a[i];
  printf("%d\n", (int)ans);
  return 0;
}
