We'll define *S*(*n*) for positive integer *n* as follows: the number of the *n*'s digits in the decimal base. For example, *S*(893) = 3, *S*(114514) = 6.

You want to make a consecutive integer sequence starting from number *m* (*m*, *m* + 1, ...). But you need to pay *S*(*n*)·*k* to add the number *n* to the sequence.

You can spend a cost up to *w*, and you want to make the sequence as long as possible. Write a program that tells sequence's maximum length.
The first line contains three integers *w* (1 ≤ *w* ≤ 10<sup class="upper-index">16</sup>), *m* (1 ≤ *m* ≤ 10<sup class="upper-index">16</sup>), *k* (1 ≤ *k* ≤ 10<sup class="upper-index">9</sup>).

Please, do not write the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64d specifier.
import math

total_money, start, k = [int(i) for i in input().split()]


numbers_bought = 0
cost = 0
current = start

starting_magnitude = len(str(start))

for magnitude in range(starting_magnitude, 16):
    steps = 10**magnitude - start

    steps_cost = steps * magnitude * k

    if cost + steps_cost > total_money:
        #print("Ok, stopping at mag", magnitude)
        break
    else:
        #print("Ok, continuing to next mag", magnitude+1)
        cost += steps_cost
    
    numbers_bought += steps 

number_cost = magnitude * k
money_remaining = total_money - cost

numbers_I_can_buy = money_remaining//number_cost

final_cost = cost + numbers_I_can_buy * number_cost

total_numbers = numbers_bought + numbers_I_can_buy

'''
print("Current cost:", cost)
print("Money remaining:", money_remaining)
print("Number cost: ", number_cost)
print("Numbers I can buy: ", numbers_I_can_buy)

print("Final cost: ", final_cost)
print("Numbers, total numbers: ", numbers_bought, total_numbers)
'''


print(total_numbers)

			 	   							 	 		   	 		   	