#include <bits/stdc++.h>
using namespace std;
const int MAX = 10100;
int arr[MAX], n, m, k;
int main() {
  cin >> n >> m >> k;
  int s = (n + 1) / 2;
  long long mn = 1LL * (m / s) * k;
  if (!(n & 1)) mn = 0;
  for (int i = 0; i < n; ++i) {
    cin >> arr[i];
    if (!(i & 1)) mn = min(1LL * arr[i], mn);
  }
  cout << mn << endl;
  return 0;
}
