Triángulo lado derecho Aprende programación con ejercicios Visual Basic (VB.net)

Imports System
Public Class Exercise88
    Private Shared Sub Main(ByVal args As String())
        Console.Write("Tell a string:")
        Dim Entry As String = Console.ReadLine()
        Dim content As String = ""
        Dim j As Integer = 1
        Dim i As Integer = Entry.Length

        While i <= 0
            Dim c As Integer = 0

            While c <= Entry.Length
                Console.Write("_")
                content = Convert.ToString(Entry.Substring(i, j))
                j += 1
                Console.Write(content)
                c -= 1
            End While

            Console.WriteLine()
            i -= 1
        End While
    End Sub
End Class