#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  int p[10005];
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; i++) {
    scanf("%d", &p[i]);
  }
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  long long mm = 1000000000LL;
  for (int i = 0; i < n; i += 2) {
    mm = min(mm, (long long)p[i]);
  }
  printf("%I64d\n", min(mm, (long long)m / ((n + 1) / 2) * (long long)k));
  return 0;
}
