using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace CsharpSpiral {
    partial class Program {
        //https://qiita.com/NotFounds/items/7b166af69a6f52a332de
        static void Main(string[] args) {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);
            new Program().Solve(new ConsoleInput(Console.In, ' '));
            Console.Out.Flush();
        }
        long lesserChoice(int range, int c) {
            long res = Enumerable.Range(0, range).Sum(i => tmp[c - 1, i]);
            return res;
        }
        public void Solve(ConsoleInput cin) {
            int[] N = cin.Read.Select(c => int.Parse(c.ToString())).ToArray();
            var tmp = new long[3, 100];
            var K = cin.ReadInt;
            //#{(j+1)-digits : which has exactly i+1 non-zero digits}
            tmp[0, 0] = 9;
            for(int i = 1; i < 100; i++) {
                tmp[0, i] = 9;
                tmp[1, i] = Enumerable.Range(1, i).Sum(j=> tmp[0, j - 1]) * 9;
                tmp[2, i] = Enumerable.Range(1, i).Sum(j => tmp[1, j - 1]) * 9;
            }
            long res = 0;
            
            int ssd = N.ToList().FindIndex(1, d => d != 0);
            int tsd = N.ToList().FindIndex(ssd + 1, d => d != 0);
            switch(K) {
                case 1:
                    res = N[0] + lesserChoice(N.Length - 1, 1);
                    break;
                case 2:
                //res<= #{msd is zero} + #{msd is non-zero but less, and rest use 1 digits}
                    res = lesserChoice(N.Length - 1, 2) + (N[0] - 1) * lesserChoice(N.Length - 1, 1);
                    //res += #{msd is same and ssd is zero} + #{msd is same and ssd is non-zero} 
                    if(ssd > 0)
                        res += lesserChoice(N.Length - ssd - 1, 1) + N[ssd];
                    break;
                case 3:
                    res = lesserChoice(N.Length - 1, 3) + (N[0] - 1) * lesserChoice(N.Length - 1, 2);
                    if(ssd > 0)
                        res += lesserChoice(N.Length - ssd - 1, 2) + (N[ssd] - 1) * lesserChoice(N.Length - ssd - 1, 1);
                    if(tsd > 0)
                        res += lesserChoice(N.Length - tsd - 1, 1) + N[tsd];
                    break;
                default:break;
            }
            Console.WriteLine(res);
        }
        long usage1(int N, int msd) {
            return msd + 9 * (N - 1);
        }

    }
    static class ExtendClass {
        public static void Swap<T>(this T[] X, int i, int j) {
            T tmp = X[i];
            X[i] = X[j];
            X[j] = tmp;
        }
        public static string Join<T>(this T[] X, string separator = " ") => string.Join(separator, X);
        public static S[] Clone<S>(this S[] src) where S : struct {
            var res = new S[src.Length];
            Array.Copy(src, res, src.Length);
            return res;
        }
    }

    class ConsoleInput {
        private readonly TextReader _stream;
        private char _separator = ' ';
        private Queue<string> inputStream;
        public ConsoleInput(TextReader stream, char separator = ' ') {
            this._separator = separator;
            this._stream = stream;
            inputStream = new Queue<string>();
        }
        public string Read {
            get {
                if(inputStream.Count != 0) return inputStream.Dequeue();
                string[] tmp = _stream.ReadLine().Split(_separator);
                for(int i = 0; i < tmp.Length; ++i)
                    inputStream.Enqueue(tmp[i]);
                return inputStream.Dequeue();
            }
        }
        public string ReadLine { get { return _stream.ReadLine(); } }
        public int ReadInt { get { return int.Parse(Read); } }
        public long ReadLong { get { return long.Parse(Read); } }
        public double ReadDouble { get { return double.Parse(Read); } }
        public string[] ReadStrArray(long N) {
            var ret = new string[N];
            for(long i = 0; i < N; ++i)
                ret[i] = Read;
            return ret;
        }
        public int[] ReadIntArray(long N) { var ret = new int[N]; for(long i = 0; i < N; ++i) ret[i] = ReadInt; return ret; }
        public long[] ReadLongArray(long N) { var ret = new long[N]; for(long i = 0; i < N; ++i) ret[i] = ReadLong; return ret; }
    }
}
