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.*;
public class bb {
public static void main(String[] args)
{
    Scanner input = new Scanner(System.in);
    long w = input.nextLong(), m = input.nextLong(), k = input.nextLong();
    w /= k;
    int len = (m+"").length();
    long res = 0;
    long allowed = getTenPow(len) - m;
    while(true)
    {
        long canMake = w/len;
        long make = Math.min(allowed, canMake);
        res += make;
        w -= len*make;
        if(w<=len) break;
        len++;
        allowed = getTenPow(len) - getTenPow(len-1);
    }
    System.out.println(res);
}
static long getTenPow(int len)
{
    long res = 1;
    for(int i = 0; i<len; i++) res *= 10;
    return res;
}
}
