Module Module1

    Sub Main()
        Dim GTIN(6) As Integer
        For c = 0 To 6 ' c = counter up to 7
            Console.WriteLine("Enter number " & (c + 1)) ' asks the user to enter a number until counter reaches 7
            'continually asks the user to enter the GTIN numbers until the  7th number is entered
            GTIN(c) = Console.ReadLine
            If GTIN(c) < 0 Or GTIN(c) > 49 Then
                'making sure that the GTIN number is between 0 and 49 if not a message is outputted
                Console.WriteLine("Invalid number entered, number must be between 0 and 49, enter it again")
                ' outputs this message when a number is over 49 or a minus
                GTIN(c) = Console.ReadLine
            End If
        Next

    End Sub

End Module