#include <bits/stdc++.h>
using namespace std;
long long a[10010];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  if (m < ((n + 1) / 2)) {
    cout << 0;
    return 0;
  }
  long long can = m / ((n + 1) / 2) * k;
  long long mn = 1e9;
  for (long long i = 1; i <= n; ++i) {
    cin >> a[i];
    if (i & 1) mn = min(mn, a[i]);
  }
  cout << min(mn, can) << endl;
  return 0;
}
