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.Scanner;

public class Main {

    private static Scanner entrada;
    private static long w, m, k, result;

    private static void solver() {
        int aux;
        while (true) {
            aux = Long.toString(m).length();
            long numb = (long) Math.pow(10, aux);
            long a = numb - m;
            if (a * aux < w) {
                w -= a * aux;
                m = numb;
                result += a;
            } else {
                result += (w / (aux));
                break;
            }
        }
    }

    public static void main(String[] args) {
        entrada = new Scanner(System.in);
        w = entrada.nextLong();
        m = entrada.nextLong();
        k = entrada.nextLong();
        w /= k;
        result = 0;
        solver();
        System.out.println(result);
    }

    

}