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;

/**
 * Created with IntelliJ IDEA.
 * User: xueyichen
 * Date: 12/13/13
 * Time: 11:33 PM
 * To change this template use File | Settings | File Templates.
 */
public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        while (cin.hasNext()) {
            long w = cin.nextLong();
            long m = cin.nextLong();
            long k = cin.nextLong();
            long v = w / k;
            long ans = 0;
            for(int i=1;i<=17;++i) {
                long max = (long)Math.pow(10,i) - 1;
                if(max >=m) {
                    long cost = (max - m + 1) * i;
                    if(cost > v) {
                        ans += v / i ;
                        break;
                    }
                    ans += cost / i;
                    m = max + 1;
                    v -= cost;
                }
            }
            System.out.println(ans);
        }
    }
}
