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
// practice with kaiboy
import java.io.*;
import java.util.*;

public class CF373B extends PrintWriter {
	CF373B() { super(System.out, true); }
	Scanner sc = new Scanner(System.in);
	public static void main(String[] $) {
		CF373B o = new CF373B(); o.main(); o.flush();
	}

	void main() {
		long w = sc.nextLong();
		long m = sc.nextLong();
		int k = sc.nextInt();
		w /= k;
		long n = m - 1, x = 9; k = 1;
		while (n > 0) {
			if (n < x) {
				w += n * k;
				break;
			}
			w += x * k;
			n -= x;
			x *= 10; k++;
		}
		n = 0; x = 9; k = 1;
		while (w > 0) {
			if (w / k < x) {
				n += w / k;
				break;
			}
			w -= x * k;
			n += x;
			x *= 10; k++;
		}
		println(n - (m - 1));
	}
}
