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 Vanya_and_Lanterns {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        long cost = input.nextLong();
        long first = input.nextLong();
        long cost_per_unit = input.nextLong();
        String num;
        long sum ,len,ten,counter=0;
                
        cost = cost / cost_per_unit;
        
        while (cost > 0) {
            num = "" + first;
            len = num.length();
            ten = (long) Math.pow(10, len);
            if (cost >= len * (ten - first)) {
                cost -=len * (ten - first);
                counter+=ten-first;
                first=ten;

            }
            else{
                counter+=cost/len;
                cost=0;
            }

        }

        System.out.println(counter);

    }
}