#include <bits/stdc++.h>
using namespace std;
int a[10005];
int main() {
  int n, m, k, i, j;
  scanf("%d%d%d", &n, &m, &k);
  if (n % 2 == 0 || n % 2 == 1 && m < (n + 1) / 2) {
    printf("0");
    return 0;
  }
  for (i = 0; i < n; ++i) scanf("%d", &a[i]);
  int s = (n + 1) / 2;
  int t = 100005;
  for (i = 0; i < n; i += 2)
    if (a[i] < t) t = a[i];
  long long res = (long long)k * (m / s);
  res = min(res, (long long)t);
  printf("%d", res);
  return 0;
}
