#include <bits/stdc++.h>
using namespace std;
int n, k, m;
int a[10009];
unsigned long long int num;
int MIN;
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  m = m / (n / 2 + 1);
  MIN = 999999999;
  for (int i = 0; i < n; i++) {
    if (i % 2 == 0) {
      if (a[i] < MIN) MIN = a[i];
    }
  }
  num = (long long int)m * k;
  if (MIN < num) num = MIN;
  printf("%lld\n", num);
  return 0;
}
