C171 Sudden change in front of the door

My home was on the ninth floor, which was the last floor. There was no elevator in this old residential area, so I walked up the stairs step by step.

Although this kind of house seems to have no class, but I do not intend to change rooms, there are still my parents' memories inside. The only drawback was that there was only one family on each floor, which made it seem a little deserted