from math import log
sum_answers = 0
i=0
while i < 10**11:
    if i == f(i):
        sum_answers+=i
        i+=1

    else:
        difference = i-f(i)
        if difference < 0:
            i+=abs(difference)

        else:
            number_of_digits = len(str(i))
            max_number_within_same_range = 10**(int(log(i, 10))+1)
            i += max(min(difference//number_of_digits, max_number_within_same_range-i),1)