#include <bits/stdc++.h>
using namespace std;
const double EPS = 1e-9;
const long long INF = 1000000000000000000;
const char *in_file = "input.txt";
const char *out_file = "output.txt";
long long n, m, k;
vector<long long> v;
int main() {
  cin >> n >> m >> k;
  v.resize(n);
  for (int _n(n), i(0); i < _n; i++) cin >> v[i];
  if (n % 2 == 0 || m < (n + 1) / 2) {
    cout << 0 << endl;
    return 0;
  }
  long long mm = 1000000;
  for (int _n(n), i(0); i < _n; i++)
    if (i % 2 == 0) mm = min(mm, v[i]);
  long long num = m / ((n + 1) / 2);
  long long kpt = num * k;
  long long res = min(mm, kpt);
  cout << res << endl;
}
