Why are there usually odd numbers of stairs?

The number of stairs must be an odd number. There are two ways to say it: one is: the total number of steps for a single staircase is odd; the other is that the total number of steps on each floor is an odd number. The reason is that when people go up stairs, they move forward, backward, forward, backward, and forward. The odd number is "advance" and the even number is "retreat". Therefore, people's implication of "jin" is to attract wealth and gain promotion. Coincidentally, in ancient Huizhou residential buildings, most of the stairs were opened on the right side of the main hall and painting hall. However, in order to make money, some people saw water coming from the left side of their houses. Therefore, the stairs were placed to go upstairs from the left. At the same time, the number of stairs is all odd (odd) numbers, and the odd number is the number of days. The stairs are made of wood. There is a stone slab at the foot of the stairs to form an even number (the number of the ground) with the stairs, which means "the sky and the earth are connected". At the same time, the stone slabs support the stairs. Stablize.