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 Making_Sequences_is_Fun {

    public static void main(String[] args) {
        int k;
        double w,m,compare,mhave,wcan,use,r=0;
        Scanner s = new Scanner (System.in);
        w=s.nextDouble();m=s.nextDouble();k=s.nextInt();
        w= (long)w / (long)k;
        int len = ((long)m+"").length();
        String str="1";
        for (int i=1;i<len;i++) str+="0";
        
        while (w>=str.length()){
            len=str.length();
            str += "0";
            compare = Double.parseDouble(str);
            mhave = compare-m;
            wcan = (long)w/(long)len;
            use = Math.min(mhave, wcan);
            w -= use*len;
            m = compare;
            r+=use;
        }
        System.out.println((long)r);
    }
}