#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a[10000];
  long long n, m, k;
  cin >> n >> m >> k;
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
  }
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long inf = 10000000;
  long long v = inf;
  for (long long i = 0; i < n; i += 2) v = min(v, a[i]);
  long long cnt = m / (n / 2 + 1);
  cout << min(cnt * k, v) << endl;
  return 0;
}
