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.*;

public class B
{
	public static void main(String args[])
	{
		Scanner sc = new Scanner(System.in);
		long w = sc.nextLong();
		long m = sc.nextLong();
		long k = sc.nextLong();


		long currLength = Long.toString(m).length();
		long pow = 1;
		long left = 1;
		for(int i = 0; i < currLength; i++)
			pow *= 10;
		left = pow - m;
		// System.out.println(pow + " " + m);
		long count = 0;
		while(w/(currLength*k) > 0)
		{
			long toAdd = Math.min(left,w/(currLength*k));
			count += toAdd;
			// System.out.println("--->"+ toAdd);
			w -= toAdd*(currLength*k);
			left = pow*10 - pow;
			currLength++;
			pow*=10;
			// System.out.println(pow);
		}	
		System.out.println(count);
	}
}