Question 7
On the pizarrón there was written a 100-digit number with the last three digits at the right equal to $999$. Under this number, using exactly the same digits, but in another order, Luciano writes a new 100-digit number: leave the last three $999$, and voluntarily exchange the first $97$ digits. This operation is repeated once and again, until numbers of $100$ digits are written on the $99$ icon. Next, add these $99$ numbers, and divide them by $72$. Calculate the remainder of the division that Luciano makes.