The program works as follow:- For every number n, n and n - 1 are converted to base 3- The program compare the digits, the number of differences is added to total
By observation, we can see that:- For every number n, most of the time the difference is 1- If n is divisible by 3, the difference is 2- If n is divisible by 3, the difference is 3, and so on
Final program:
```def count3(n):    sum = 0    while (n > 0):        sum += n        n //= 3    return sum
print(count3(523693181734689806809285195318))```
Flag: `csictf{785539772602034710213927792950}`