#include <bits/stdc++.h>
int main() {
  long long a[10005], i, j, n, m, k, p = 0, pmax, min = 100000, mini;
  scanf(" %lld %lld %lld", &n, &m, &k);
  for (i = 0; i < n; i++) {
    scanf(" %lld", a + i);
    if (i % 2 == 0 && a[i] < min) {
      mini = i;
      min = a[i];
    }
  }
  if (n % 2 == 0 || m < (n + 1) / 2) {
    printf("0");
    return 0;
  } else {
    pmax = k * (m / ((n + 1) / 2));
    if (pmax > min)
      printf("%lld\n", min);
    else
      printf("%lld\n", pmax);
  }
  return 0;
}
