#include <bits/stdc++.h>
using namespace std;
int main(int argc, char* const argv[]) {
  long long n, m, k;
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long maxSteal = (m / (n / 2 + 1)) * k;
  vector<long long> v(n);
  for (int i = 0; i < (n); ++i) cin >> v[i];
  long long canSteal = v[0];
  for (int i = 2; i < n; i += 2) canSteal = min(canSteal, v[i]);
  cout << min(maxSteal, canSteal) << endl;
  return 0;
}
