Public Class Program
  Shared Sub Main()
    Dim s As String = Console.ReadLine()
    Dim ans As String = "Yes"
    For i As Integer = 0 To s.Length() - 1
      If (i + 1) Mod 2 = 1 Then
        If s(i) = "L" Then
          ans = "No"
          Exit For
        End If
      Else
        If s(i) = "R" Then
          ans = "No"
          Exit For
        End If
      End If
    Next
    Console.WriteLine(ans)
  End Sub
End Class