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.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Codeforces {
  public static void main(String[] args) {
    CustomInputReader in = new CustomInputReader(System.in);
    TaskB solver = new TaskB();
    solver.solve(in);
  }
}

class TaskB {
  public void solve(CustomInputReader in) {
    long w = in.nextLong(), m = in.nextLong(), k = in.nextLong();
    long t = 1, ans = 0;
    w /= k;
    int length = 0;
    while (t < m) {
      length++;
      t *= 10;
    }
    while (w >= (t - m) * length) {
      w -= (t - m) * length;
      ans += t - m;
      m = t;
      t *= 10;
      length++;
    }
    ans += w / length;
    System.out.println(ans);
  }
}

class CustomInputReader {
  public BufferedReader reader;
  public StringTokenizer tokenizer;

  public CustomInputReader(InputStream stream) {
    reader = new BufferedReader(new InputStreamReader(stream));
    tokenizer = null;
  }

  public String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new StringTokenizer(reader.readLine());
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  public int nextInt() {
    return Integer.parseInt(next());
  }

  public long nextLong() {
    return Long.parseLong(next());
  }
}
