Imports System

​

Module Program

    Sub Main()

        Dim FactNumber as Integer

        FactNumber = Console.ReadLine()

        Dim Factorial as integer = FactorialNumber(FactNumber)

        Console.WriteLine(" Factorial is:"& Factorial)

    End Sub

        Function FactorialNumber(Byval FactNumber as Integer) as Integer

        IF Factnumber < 1

            return 1

        else

                return FactNumber * FactorialNumber(FactNumber -1)

        End If

        End Function

End Module

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