Module Module1
   
   Sub Main()
   Dim input As Integer
   Dim result As Double
   
          Console.WriteLine("Please input your value for factorial")
          input = Console.ReadLine
   
          result = calculateFactorial(input)
   
          Console.WriteLine(result)
          Console.Read()
   
   End Sub
   
   Function calculateFactorial(ByVal number As Integer) As Double
   Dim factorial As Double = 1.0
   For i As Double = 1.0 To number
              factorial = factorial * i
   Next
   Return factorial
   End Function
   
  End Module