Module Module1

    Sub Main()

        Dim S As String = Console.ReadLine()
        Dim l(3) As String
        Dim i As Integer

        For i = 1 To Len(S) Step 2
            If Mid(S, i, 1) = "L" Then
                Console.WriteLine("No")
                Exit Sub
            End If
            If i <= Len(S) AndAlso Mid(S, i + 1, 1) = "R" Then
                Console.WriteLine("No")
                Exit Sub
            End If
        Next

        Console.WriteLine("Yes")

        'Console.ReadLine()

    End Sub

End Module
