#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> m >> k;
  if (n % 2 == 0)
    cout << 0 << endl;
  else {
    long long p = (long long)m / (long long)((n + 1) / 2) * (long long)k;
    for (int i = 0; i < n; i++) {
      int x;
      cin >> x;
      if ((i % 2 == 0) && (x < p)) p = x;
    }
    cout << p << endl;
  }
  return 0;
}
