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;
import java.util.StringTokenizer;

public class MakingSequencesIsFun {
    public static long[] pow = new long[20];
    public static void main(String[] args) throws IOException {
        BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(f.readLine());
        long w = Long.parseLong(st.nextToken());
        long m = Long.parseLong(st.nextToken());
        long k = Long.parseLong(st.nextToken());
        w /= k;
        pow[0] = 1;
        for (int i = 1; i < pow.length; i++)
            pow[i] = pow[i-1]*10;
        long lo = m-1;
        long hi = 1000000000000000000l;
        while (true) {
            long mid = (lo+hi)/2;
            if (f(m,mid) <= w && f(m,mid+1) > w) {
                System.out.println(mid-m+1);
                return;
            }

            if (f(m,mid) <= w)
                lo = mid+1;
            else
                hi = mid-1;
        }
    }
    
    public static long f(long m, long n) {
        if (m > n)
            return 0;
        long sum = 0;
        for (int d = 1; d <= 17; d++) {
            long a = pow[d-1];
            long b = pow[d]-1;
            a = Math.max(a, m);
            b = Math.min(b, n);
            if (a <= b)
                sum += (b-a+1)*d;
        }
        return sum;
    }
}
