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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;


public class MakingSequencesisFun {

	/**
	 * @param args
	 * @throws IOException 
	 */
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		
		String [] array = br.readLine().split(" ");
		long w = Long.parseLong(array[0]);
		long m = Long.parseLong(array[1]);
		long k = Long.parseLong(array[2]);
		
		long count = 0;
		while(true) {
			int s = (m + "").length();
			long nextPower = (long)(Math.pow(10, s));
			long c = nextPower - m;
			
			long possible = w / (k * s);
			long taken = possible < c ? possible : c;
			count += taken;
			w -= taken * k * s;
			m = nextPower;
			
			if (possible <= c) {
				break;
			}
		}
		System.out.println(count);
	}

}
