c++ yardım

Module Module1
    Sub Main()
        Console.WriteLine("{0}", MyFunction(3, 3))
        Console.ReadKey()
 
    End Sub
 
    Public Function MyFunction(ByVal k As Integer, ByVal t As Integer) As Integer
        Dim a As Integer = 0
        For i = 1 To k
            a = a + CalculateFactorial(i) + CalculateMultiplication(i, t)
        Next
        Return a
    End Function
 
    Public Function CalculateMultiplication(ByVal m As Integer, ByVal t As Integer) As Integer
        Dim a As Integer = 1
        For i = m To t
            a = a * 2 * i
        Next
        Return a
    End Function
 
    Public Function CalculateFactorial(ByVal n As Integer) As Integer
        Dim a As Integer = 1
        For i As Integer = 1 To n
            a = a * i
        Next
        Return a
    End Function
End Module