Imports System

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Public Module Module1

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    Public Sub Main()

        dim marks(5) as integer

        for x = 1 to 5

            marks(x) = console.readline()

            if marks(x) > 50 then

                console.WriteLine("invalid marks")

            else if marks(x) < 0 then

                console.WriteLine("invalid marks")

            end if

        next

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        if 0 < marks(5) < 50 then

            console.writeline(marks(5) / 50 * 100 & ("%"))

        end if

    End Sub

End Module

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