#include <bits/stdc++.h>
using namespace std;
const int MAXN = 10000 + 100;
long long int n, m, k, d[MAXN];
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < (int)(n); i++) cin >> d[i];
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long int res = 1LL << 60;
  for (int i = 0; i < n; i += 2) res = min(res, d[i]);
  long long int cost = (n + 1) / 2;
  res = min(res, k * (m / cost));
  cout << res << endl;
  return 0;
}
