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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;


public class ProblemB {
    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        StringTokenizer st = new StringTokenizer(in.readLine());
        long w = Long.parseLong(st.nextToken());
        long m = Long.parseLong(st.nextToken());
        long k = Long.parseLong(st.nextToken());
        long rem = w/k;
        String x = m+"";
        long dec = (long) Math.pow(10, x.length());
        long res = 0;
        while(rem>0){
            long dif = dec - m;
            int len = x.length();
            if(len!=0){
                if(rem <dif*x.length()){
                    res+=rem/(len);
                    rem = 0;
                }
                else{
                    rem -= dif*x.length();
                    res +=dif;
                }
            }
            m=dec;
            dec*=10;
            x+="1";
        }
        out.println(res);
        in.close();
        out.close();
    }

}
