def check(a)
  for i in 0..(a.size - 3) do
    for j in (i + 1)..(a.size - 2) do
      for k in (j + 1)..(a.size - 1) do
        next if a[i] <= a[j] && a[j] <= a[k]
        next if a[i] >= a[j] && a[j] >= a[k]
        ad = a.dup
        ad.delete_at(k)
        ad.delete_at(j)
        ad.delete_at(i)
        return [i, j, k] unless check(ad)
      end
    end
  end

  return nil
end

gets
A = gets.split.map(&:to_i)
ans = check(A)
puts ans ? ans.join(" ") : -1