5.2. Find the sum of the digits in the decimal representation of the integer part of the number $\sqrt{\underbrace{11 \ldots 11}_{2018} \underbrace{55 \ldots 55}_{2017} 6}$.
Answer: 6055 (the number from the condition of the problem is $\underbrace{33 \ldots 33}_{2017} 4$ ).