defmodule Main do
  def main do
    IO.read(:line)
    |> String.trim()
    |> solve
    |> IO.puts()
  end

  def solve(s) do
    t = s |> String.to_charlist()

    cond do
      0..((t |> length |> div(2)) - 1)
      |> Enum.all?(fn i ->
        t |> Enum.at(2 * i) != ' ' |> hd &&
            t |> Enum.at(2 * i + 1) == ' ' |> hd
      end) ->
        "Yes"

      true ->
        "No"
    end
  end
end