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
from sys import stdin


def cal(m1):
    all, cur = 0, 0
    while cur <= m1:
        new = 10 ** len(str(cur))
        all += (min(m1 + 1, new) - cur) * len(str(cur))
        cur = new
    return all


w, m, k = map(int, stdin.readline().split())
tem = cal(m - 1)

be, en, ans = m, 10 ** 20, m - 1
while be <= en:
    md = (be + en) >> 1
    val = (cal(md) - tem) * k
    if val <= w:
        be, ans = md + 1, md
    else:
        en = md - 1

print(ans - m + 1)
