#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, k, result1, result2, x1, x2;
  cin >> n >> k >> m;
  cin >> x1;
  for (int i = 0; i < n - 1; i++) {
    cin >> x2;
    if (i % 2 == 1 && x2 < x1) x1 = x2;
  }
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  result1 = x1;
  result2 = m * (k / ((n + 1) / 2));
  cout << min(result1, result2);
  return 0;
}
