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 Main {

	private static Scanner input;
	private static long w, m, k, ans;

	public static void main(String[] args) {
		input = new Scanner(System.in);
		w = input.nextLong();
		m = input.nextLong();
		k = input.nextLong();
		w /= k;
		ans = 0;
		solver();
		System.out.println(ans);
	}

	private static void solver() {
		int aux;
		while (true) {
			aux = Long.toString(m).length();
			long numb = (long) Math.pow(10, aux);
			long a = numb - m;
			if (a * aux < w) {
				w -= a * aux;
				m = numb;
				ans += a;
			} else {
				ans += (w / (aux));
				break;
			}
		}
	}

}
