Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim num As Integer = Val(TextBox1.Text)
        MessageBox.Show("a")
        If num >= 100 Then
            MessageBox.Show("b")
        ElseIf num >= 50 Then
            MessageBox.Show("c")
            If num >= 75 Then
                MessageBox.Show("d")
                If num >= 80 Then
                    MessageBox.Show("e")
                ElseIf num >= 90 Then
                    MessageBox.Show("f")
                ElseIf num >= 77 Then
                    MessageBox.Show("g")
                End If
                MessageBox.Show("h")
                If num >= 73 Then
                    MessageBox.Show("i")
                Else
                    MessageBox.Show("j")
                End If
                MessageBox.Show("k")
            End If
            MessageBox.Show("l")
        End If
        MessageBox.Show("m")
        If num >= 2 Then
            MessageBox.Show("n")
        End If
        MessageBox.Show("o")


    End Sub
End Class