#plus_or_minus_one

The main building of Moscow State University consists of several sectors. The highest tower with a spire is sector A, it is educational. Side sectors B and C adjoin it - dormitories for students. Floors in different sectors differ in height. Because of this, for example, it turns out that transitions from the 13th floor of sector A lead to the 19th floor of sectors B and C.
What is the ratio of the floor height of sector A to sector B?