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
#!/usr/bin/env python

def get_max_sequence(w, m, k):
    next_num = '1' + '0' * len(str(m))
    cost = 0
    seq_len = 0

    while cost < w:
        num_seq = int(next_num) - m
        if num_seq * len(str(m)) * k + cost < w:
            cost += num_seq * len(str(m)) * k
            seq_len += num_seq 
            m = int(next_num)
            next_num = '1' + '0' * len(str(m))
            num_seq = int(next_num) - m
        else:
            seq_len += int((w - cost) / (k * len(str(m))))
            cost = w
    return seq_len

if __name__ == '__main__':
    w, m, k = map(int, raw_input().split())
    print get_max_sequence(w, m, k)
