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
import java.util.*;

public class Main {
    
    public static void main(String[] args) throws Exception {
        Scanner scan = new Scanner(System.in);
        long w = scan.nextLong();
        long m = scan.nextLong();
        int k = scan.nextInt();
        
        long res = 0;
        long bound = 1;
        long s = 0;
        while (bound <= m) {
            bound *= 10;
            s++;
        }
        while (true) {
            long base = s * k;
            long num = w / base;
            if (num == 0) {
                break;
            }
            long require = Math.min(num, bound - m);
            w -= require * base;
            res += require;
            m = bound;
            bound *= 10;
            s++;
        }
        
        System.out.println(res);
    }
}