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.
def digits (n):
    arr = str(n)
    return len(arr)

total = 0
cont = 0

w,m,k = map(int,input().split())

d = digits(m)
num = 1
for i in range(0,d):
    num *= 10

while True:
    dif = num - m
    tmp = digits(m) * k * dif
    if tmp + total > w:
        dif_tmp = w-total
        dif_tmp /= (digits(m) * k )
        total += dif_tmp
        cont += dif_tmp
        break
    else:
        cont += dif
        total += tmp
        m = tmp
        num *= 10
        d += 1

print(int(cont))