#include <bits/stdc++.h>
using namespace std;
long long a[1 << 14];
int main() {
  int i, j;
  long long n, m, k;
  cin >> n >> m >> k;
  for (i = 0; i < n; ++i) cin >> a[i];
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  long long maxi = (a[0] + a[n - 1]) / 2;
  for (i = 0; i < n; i += 2) {
    maxi = min(maxi, a[i]);
  }
  long long res;
  if (m <= n / 2) {
    printf("0\n");
    return 0;
  }
  int num = m / (n / 2 + 1);
  res = num * k;
  res = min(res, maxi);
  printf("%d\n", res);
  return 0;
}
