#include <bits/stdc++.h>
using namespace std;
int gcd(int x, int y) { return x == 0 ? y : gcd(y % x, x); }
int a[10001];
int main() {
  int n, m, k, i;
  scanf("%d", &n);
  scanf("%d", &m);
  scanf("%d", &k);
  int flag = 0;
  long long ans = 0x7ffffffff;
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    if (i % 2 == 0) ans = ((ans) < (a[i]) ? (ans) : (a[i]));
  }
  if (ans == 0 || n % 2 == 0 || m < (n + 1) / 2) {
    puts("0");
    return 0;
  }
  ans = ((ans) < ((long long)m / ((n + 1) / 2) * k)
             ? (ans)
             : ((long long)m / ((n + 1) / 2) * k));
  printf("%lld", ans);
  puts("");
  return 0;
}
