Sub bosd()
For i = 2 To Range("A65536").End(3).Row
If Cells(i, 2).Value = "" Then
If Cells(i, 1).Value = 420 Then
Cells(i, 2).Value = "AA"
ElseIf Cells(i, 1).Value = 440 Then
Cells(i, 2).Value = "BB"
ElseIf Cells(i, 1).Value = 460 Then
Cells(i, 2).Value = "CC"
End If
End If
Next
End Sub