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.

Input

The first line contains three integers w (1 ≤ w ≤ 1016), m (1 ≤ m ≤ 1016), k (1 ≤ k ≤ 109).

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.

Output

The first line should contain a single integer — the answer to the problem.

Examples

Input

9 1 1


Output

9


Input

77 7 7


Output

7


Input

114 5 14


Output

6


Input

1 1 2


Output

0
# -*- coding: utf-8 -*-
import sys

w, m, k = (int(x) for x in sys.stdin.readline().split(' '))
n = w // k

def S(x):
    i = 0
    while x:
        i += 1
        x //= 10
    return i

c = 0
l = S(m)
while True:
    num = 10 ** l - m
    if n > num * l:
        n -= num * l
        c += num
        m = 10 ** l
        l += 1
    else:
        c += n // l
        break
print(c)