#include <bits/stdc++.h>
using namespace std;
long long n, m, i, j, k, l;
long long p[10004], ans;
int main() {
  cin >> n >> m >> k;
  for (int i_ = 0; i_ < n; ++i_) cin >> p[i_];
  ;
  ans = 0;
  if (n & 1) {
    if (m >= n / 2 + 1) {
      int mn = 2e9;
      for (i = 0; i < n; i += 2) mn = ((mn) < (p[i]) ? (mn) : (p[i]));
      l = m / (n / 2 + 1);
      ans = ((mn) < (l * k) ? (mn) : (l * k));
    }
  }
  cout << ans << endl;
  return 0;
}
