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 EsB {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long w = scan.nextLong();
		long m = scan.nextLong();
		long k = scan.nextLong();
		
		long counter = 0;
		
		w = w/k;
				
		while(true){
			long log = (long)((Math.log10(m))+1);
			long log1 = log;
			long pow = (long) Math.pow(10, log1);
			long dif = pow-m;
			
			if(w>=dif*log){
				counter = counter+dif;
				w=w-dif*log;
				m=pow;
			}else{
				long x = w/log;
				if(x==0){
					System.out.println(counter);
					break;
				}else{
					counter = counter +x;
					w = w-x*log;
					m=m+x;
				}
			}
			
			
			
			/*long length = 
			w = w-length;
			if(w>=0){
				counter = counter+1;
				m=m+1;
			}else{
				System.out.println(counter);
				break;
			}*/
		}
		
		
	}
	
	
	
	

}
