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


//System.out.println();
public class Main implements Runnable { //クラス名はMain

    public static void main(String[] args) {
    	Thread.setDefaultUncaughtExceptionHandler((t,e)->System.exit(1));
        new Thread(null, new Main(), "", 16 * 1024 * 1024).start(); //16MBスタックを確保して実行
    }

    public void run() {
    	FastScanner sc = new FastScanner(System.in);
        long n = sc.nextLong();
        int k = sc.nextInt();
        long count = 0;
        for(long i=1;i<=n;i++) {
        	String notZero = Long.toString(i).replaceAll("[0]", "");
        	if (notZero.length() == k) {
        		count +=1;
        	}
        }
        System.out.println(count);

    }
}

//高速なScanner
class FastScanner {
	private BufferedReader reader = null;
	private StringTokenizer tokenizer = null;

	public FastScanner(InputStream in) {
		reader = new BufferedReader(new InputStreamReader(in));
		tokenizer = null;
	}

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

	public String nextLine() {
		if (tokenizer == null || !tokenizer.hasMoreTokens()) {
			try {
				return reader.readLine();
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return tokenizer.nextToken("\n");
	}

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

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

	public double nextDouble() {
		return Double.parseDouble(next());
	}

	public int[] nextIntArray(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = nextInt();
		return a;
	}

	public long[] nextLongArray(int n) {
		long[] a = new long[n];
		for (int i = 0; i < n; i++)
			a[i] = nextLong();
		return a;
	}
}
