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 B219Div2 
{
	public static void main(String[] args) throws Exception
	{
		Scanner in = new Scanner(System.in);
		long w = in.nextLong(), m = in.nextLong(), k = in.nextLong();
		w /= k;
		int len = (m+"").length();
		String str = "1";
		for (int i = 1; i < len; ++i) str += "0";
		long ret = 0;
		while (w >= str.length())
		{
			int digs = str.length();
			str += "0";
			long val = Long.parseLong(str);
			long left = val - m;
			long use = Math.min(left, w/digs);
			w -= digs*use;
			m = val;
			ret += use;
		}
		System.out.println(ret);
		in.close();
	}
}
