Lista C

Public Class Form1
    Dim X As Integer = 1
    Dim Impares As Integer
    Dim Pares As Integer
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If X > 20 Then
            Button1.Enabled = False
            MsgBox(Impares)
            MsgBox(Pares)
        Else
            ListBox1.Items.Insert(X, txtv1.Text)
        End If
        X += 1
        For Cont As Integer = 1 To ListBox1.Items.Count
            If (ListBox1.SelectedItem.Value / 2) <> 0 Then
                Impares += ListBox1.SelectedItem.Value
            Else
                Pares += ListBox1.SelectedItem.Value
            End If
        Next
    End Sub
End Class