#include <bits/stdc++.h>
using namespace std;
int n, m, k, a[10005];
int getRes() {
  if (n % 2 == 0) return 0;
  int minodd = 10000000;
  for (int i = 0; i < n; i += 2) minodd = min(minodd, a[i]);
  int moves = n / 2 + 1;
  int dperturn = m / moves;
  long long maxget = (long long)dperturn * (long long)k;
  long long res = min(maxget, (long long)minodd);
  return res;
}
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < n; i++) cin >> a[i];
  int res = getRes();
  cout << res << endl;
  return 0;
}
