#include <bits/stdc++.h>
int main() {
  long long n, m, k, i;
  long long a[10000], j, x, y, z, w;
  scanf("%lld%lld%lld", &n, &m, &k);
  for (i = 0; i < n; i++) scanf("%lld", &a[i]);
  if (n % 2 == 0)
    printf("0");
  else {
    j = (long long)m * k;
    x = n / 2 + 1;
    w = (long long)m / x;
    y = a[0];
    for (i = 0; i < n; i++) {
      if (i % 2 == 0) {
        if (a[i] < y) y = a[i];
      }
    }
    z = w * k;
    if (z >= y)
      printf("%lld", y);
    else {
      printf("%lld", z);
    }
  }
  return 0;
}
