#include <bits/stdc++.h>
using namespace std;
int a[10000];
int main() {
  int n, k, m;
  scanf("%d %d %d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  int minn = a[0];
  for (int i = 2; i < n; i += 2) {
    if (a[i] < minn) minn = a[i];
  }
  int t = (n + 1) / 2;
  long long ans = ((long long)k) * (m / t);
  if (ans > minn) ans = minn;
  printf("%I64d", ans);
  return 0;
}
