Sub Macro1()
Range("C2:C" & Range("C65535").End(xlUp).Row + 1).ClearContents
For i = 2 To Range("A65535").End(xlUp).Row
If Cells(i, 1) <> "" And Cells(i, 2) <> "" Then
For j = Cells(i, 1) To Cells(i, 2)
Range("C" & Range("C65535").End(xlUp).Row + 1) = j
Next j
Else
Range("C" & Range("C65535").End(xlUp).Row + 1) = Cells(i, 1)
End If
Next i
End Sub