Module Module1
    ' addNumsR is a recursive version of a subroutine to add a list of numbers
    ' addNumsI is an iterative version of a subroutine to add a list of numbers

    Function addNumsR(ByVal numbers As List(Of Integer)) As Integer
        Dim upper As Integer = 0

        If (numbers.Count() = 1) Then
            Return numbers(0)
        Else
            ' Find all items except the first one
            upper = numbers.Count() - 1
            Return numbers(0) + addNumsR(numbers.GetRange(1, upper))
        End If

    End Function

    Function addNumsI(ByVal numbers As List(Of Integer)) As Integer
        Dim sum As Integer = 0
        Dim num As Integer = 0

        For Each num In numbers
            sum = sum + num
        Next

        Return sum
    End Function

    Sub Main()
        Dim eat As String = ""
        Dim marks = New List(Of Integer) From {3, 6, 2, 8, 1}
        Dim total As Integer = 0

        Console.WriteLine("Recursive routine")
        total = addNumsR(marks)
        Console.WriteLine(String.Format("Total: {0}", total))

        Console.WriteLine("Iterative routine")
        total = addNumsI(marks)
        Console.WriteLine(String.Format("Total: {0}", total))

        Console.WriteLine("Any key to continue")
        eat = Console.ReadLine()
    End Sub

End Module