output_description: Print `Yes` if S is easily playable, and `No` otherwise.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: {
      "nbformat": 4,
      "nbformat_minor": 0,
      "metadata": {
          "colab": {"name": "py.py", "provenance": []},
          "kernelspec": {"name": "python3", "display_name": "Python 3"},
      },
      "cells": [
          {
              "cell_type": "code",
              "metadata": {
                  "id": "H3laJejZ8tH7",
                  "colab_type": "code",
                  "colab": {"base_uri": "https://localhost:8080/", "height": 35},
                  "outputId": "13f7e97e-3eae-44b3-ce92-df84580aa0d6",
                  "executionInfo": {
                      "status": "ok",
                      "timestamp": 1569272992629,
                      "user_tz": -540,
                      "elapsed": 1544,
                      "user": {
                          "displayName": "ryo t",
                          "photoUrl": "",
                          "userId": "15768515004963573815",
                      },
                  },
              },
              "source": ['print("a")'],
              "execution_count": 1,
              "outputs": [{"output_type": "stream", "text": ["a\n"], "name": "stdout"}],
          }
      ],
  }
  
problem_description: Statement
  
  Takahashi will do a tap dance. The dance is described by a string S where each
  character is `L`, `R`, `U`, or `D`. These characters indicate the positions on
  which Takahashi should step. He will follow these instructions one by one in
  order, starting with the first character.
  
  S is said to be _easily playable_ if and only if it satisfies both of the
  following conditions:
  
    * Every character in an odd position (1-st, 3-rd, 5-th, \ldots) is `R`, `U`, or `D`.
    * Every character in an even position (2-nd, 4-th, 6-th, \ldots) is `L`, `U`, or `D`.
  
  Your task is to print `Yes` if S is easily playable, and `No` otherwise.
samples: [{"input": "RUDLUDR", "output": "Yes\n    \n\nEvery character in an odd position (1-st, 3-rd, 5-th, 7-th) is `R`, `U`, or\n`D`.\n\nEvery character in an even position (2-nd, 4-th, 6-th) is `L`, `U`, or `D`.\n\nThus, S is easily playable.\n\n* * *"}, {"input": "DULL", "output": "No\n    \n\nThe 3-rd character is not `R`, `U`, nor `D`, so S is not easily playable.\n\n* * *"}, {"input": "UUUUUUUUUUUUUUU", "output": "Yes\n    \n\n* * *"}, {"input": "ULURU", "output": "No\n    \n\n* * *"}, {"input": "RDULULDURURLRDULRLR", "output": "Yes"}]