defmodule Main do
  
  def main do
    IO.read(:line) |> String.trim() |> String.split(" ") |> Enum.map(&String.to_integer/1) |> solve() |> IO.puts()
  end

  def solve([a1, a2, a3, a4]) when a1 < a2 and a4 < a3, do: "YES"
  def solve(_), do: "NO"

end