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
//package com.congli.codeforces;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Locale;
import java.util.StringTokenizer;

public class C219Div2B_Sequences {

	BufferedReader in;
	PrintWriter out;
	StringTokenizer tok = new StringTokenizer("");

	public static void main(String[] args) {
		C219Div2B_Sequences test = new C219Div2B_Sequences();
		test.start();
	}

	public void solve() throws IOException {
		long w = readLong();
		long m = readLong();
		long k = readLong();
		int numDigits = Long.toString(m).length();

		out.println(count(w, k, (long)Math.pow(10.0, numDigits)-m, numDigits));
	}
	
	private long count(long w, long k, long totalNum, int numDigits) {
		long realNum = w / (k*numDigits);
		if (realNum < totalNum) {
			return realNum;
		}
		return totalNum + count(w - k*totalNum*numDigits, k, 9*(long)Math.pow(10.0, numDigits), numDigits+1);
	}
	
	public void start()
	{
		try {
			long t1 = System.currentTimeMillis();
			if (System.getProperty("ONLINE_JUDGE") != null) {
				in = new BufferedReader(new InputStreamReader(System.in));
				out = new PrintWriter(System.out);
			} else {
				in = new BufferedReader(new FileReader("/Users/congli/Documents/javaworkspace/codeforces/src/com/congli/codeforces/input.txt"));
				out = new PrintWriter(System.out);
			}
			Locale.setDefault(Locale.US);
			solve();
			in.close();
			out.close();
			long t2 = System.currentTimeMillis();
			System.err.println("Time = " + (t2 - t1));
		} catch (Throwable t) {
			t.printStackTrace(System.err);
			System.exit(-1);
		}
	}
	
	public String readString() throws IOException {
		while (!tok.hasMoreTokens()) {
			tok = new StringTokenizer(in.readLine());
		}
		return tok.nextToken();
	}

	public int readInt() throws IOException {
		return Integer.parseInt(readString());
	}

	public long readLong() throws IOException {
		return Long.parseLong(readString());
	}

	public double readDouble() throws IOException {
		return Double.parseDouble(readString());
	}
}

