Imports System

Public Module Module1

    Public Sub Main()

        Console.WriteLine("Hello World")

        dim Mark as integer

        Mark = 0

        console.WriteLine("Enter Mark")

        Mark = console.ReadLine()

        if Mark > 79 THEN

            console.WriteLine("A")

        else 

            IF Mark > 59 THEN

            console.WriteLine("B")

            ELSE

                IF Mark > 49 THEN

                    console.WriteLine("C")

                else 

                    if Mark > 39 THEN

                        console.WriteLine("Fail")

                    end if

                end if

            end if

        end if

    End Sub

End Module