#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[200000];
  int n, m, k;
  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;
  }
  long long x = n / 2 + 1;
  x = m / x;
  x = x * k;
  long long res = x;
  int z1 = a[0];
  for (int i = 0; i < n; i++) {
    if (i % 2 == 1) continue;
    if (a[i] < z1) z1 = a[i];
  }
  if (res > z1) res = z1;
  printf("%d\n", (int)res);
  return 0;
}
