#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
const int N = 3e5 + 7;
long long arr[N];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  long long mn = INT_MAX;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    if (i % 2 == 0) mn = min(mn, arr[i]);
  }
  if (n % 2 == 0) {
    cout << 0 << "\n";
  } else {
    cout << min(mn, (m / (n / 2 + 1)) * k) << "\n";
  }
}
