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.*;
import java.util.*;

public class p373b_2
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.println();
        long w = sc.nextLong();
        long m = sc.nextLong();
        long k = sc.nextLong();
        long s = S(m);
        long l = 1;
        long ans = 0L;
        for(int i=0;i<s;i++) l *= 10L;
        while(w>=s*k)
        {
            long a = Math.min(w/(s*k),l-m);
            w -= a*s*k;
            m = l;
            l *= 10;
            s++;
            ans += a;
        }
        System.out.println(ans);
    }

    public static long S(long n)
    {
        int count = 0;
        while(n>0)
        {
            n /= 10;
            count++;
        }
        return count;
    }
}