#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const double eps = 1e-11;
template <class T>
void show(T a, int n) {
  for (int i = 0; i < n; ++i) cout << a[i] << ' ';
  cout << endl;
}
template <class T>
void show(T a, int r, int l) {
  for (int i = 0; i < r; ++i) show(a[i], l);
  cout << endl;
}
int a[10001];
int main() {
  int b, j, n, i, t, x, y, z;
  long long k, m, ans, ma;
  while (cin >> n >> m >> k) {
    for (i = 1; i <= n; i++) cin >> a[i];
    if (n == 1) {
      ans = k * m;
      if (ans > a[1]) ans = a[1];
      cout << ans << endl;
      continue;
    }
    if (n % 2 == 0) {
      cout << "0\n";
      continue;
    }
    ans = 0;
    ma = 100000;
    for (i = 1; i <= n; i += 2) {
      if (ma > a[i]) ma = a[i];
    }
    ans = m / ((n + 1) / 2);
    ans *= k;
    ans = min(ans, ma);
    cout << ans << endl;
  }
  return 0;
}
