#include <bits/stdc++.h>
using namespace std;
const unsigned long long MOD = 257;
int n, m, k;
long long a;
int main() {
  std::ios::sync_with_stdio(false);
  cin >> n >> m >> k;
  long long tmp = 100005;
  for (int i = 1; i <= n; i++) {
    cin >> a;
    if (tmp > a && ((i % 2) == 1)) {
      tmp = a;
    }
  }
  long long ans = 0, x = n / 2 + 1;
  if ((n % 2) && (x <= m)) {
    ans = m / x * k;
    ans = min(ans, tmp);
  }
  cout << ans << endl;
}
