#include <bits/stdc++.h>
using namespace std;
vector<long long> t;
int n, m, k;
int main() {
  cin >> n >> m >> k;
  long long mi = 2000000000;
  for (int i = 0; i < n; i++) {
    long long a;
    cin >> a;
    t.push_back(a);
    if (i % 2 == 0) {
      mi = min(mi, a);
    }
  }
  if (n / 2 + 1 > m) {
    cout << 0 << endl;
    return 0;
  }
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long step = n / 2 + 1;
  long long get = m / step;
  cout << min(mi, k * get) << endl;
}
