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 B_219 {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		long w = in.nextLong();
		long m = in.nextLong();
		long k = in.nextLong();
		
		w = w/k;
		long num = 0;
		
		while(w > 0){
			//System.out.println("w = "+w + " m="+m +" num="+num);
			int mDigits = digits(m);
			long nextTen = (long) Math.pow(10, (mDigits));
			if(mDigits*(nextTen-m) > w){
				//System.out.println("here1");
				long nn = w/mDigits;
				num += nn;
				break;
			} else {
				//System.out.println("here2");
				
				w -= mDigits*(nextTen-m);
				
				num += (nextTen-m);
				m = nextTen;
			}
			
		}
		
		System.out.println(num);
		
	}
	
	static int digits(long t){
		int ret = 0;
		while(t > 0){
			t /= 10;
			ret++;
		}
		return ret;
	}

}
