MathDB

N

cossacks split into

3

groups to discuss various issues with their friends. Cossack Taras moved from the first group to the second, cossack Andriy moved from the second to the third, and cossack Ostap - from the third group to the first. It turned out that the average height of the cossacks in the first group decreased by

8

cm, while in the second and third groups it increased by

5

cm and

8

cm, respectively.
What is

N

, if it is known that there were

9

cossacks in the first group?

Problem Statement