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 B {

    static Scanner in = new Scanner(System.in);

    public static void main(String[] args) {
        long w = in.nextLong(), m = in.nextLong(), k = in.nextLong();
        long sum = 0;
        long count = 0;
        w /= k;
        while (sum < w) {
            int b = base(m);
            long next = gen(b + 1);
            if ((next - m) * b + sum <= w) {
                sum += (next - m) * b;
                count += next - m;
                m = next;
            } else {
                long c = (w - sum) / b;
                count += c;
                sum += c * b;
                break;
            }
        }
        System.out.println(count);
    }

    static int base(long n) {
        int res = 0;
        while (n > 0) {
            res += 1;
            n /= 10;
        }
        return res;
    }

    static long gen(int b) {
        long res = 1;
        while (b > 1) {
            res *= 10;
            b--;
        }
        return res;
    }
}