using Yorukatsu044.Questions;
using Yorukatsu044.Extensions;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Yorukatsu044.Questions
{
    /// <summary>
    /// ABC154 E
    /// </summary>
    public class QuestionE : AtCoderQuestionBase
    {
        public override IEnumerable<object> Solve(TextReader inputStream)
        {
            var n = inputStream.ReadString();
            var k = inputStream.ReadInt();

            var count = new long[n.Length + 1, 2, k + 1];
            const int MayExceed = 0;
            const int Less = 1;
            count[0, MayExceed, 0] = 1;

            for (int digit = 0; digit < n.Length; digit++)
            {
                var current = n[digit] - '0';

                // 超えるかも？→超えるかも？
                if (current > 0)
                {
                    // 0以外
                    for (int i = 0; i + 1 <= k; i++)
                    {
                        count[digit + 1, MayExceed, i + 1] += count[digit, MayExceed, i];
                    }
                }
                else
                {
                    // 0
                    for (int i = 0; i <= k; i++)
                    {
                        count[digit + 1, MayExceed, i] += count[digit, MayExceed, i];
                    }
                }

                // 超えるかも？→超えない
                if (current > 1)
                {
                    // 1～max-1
                    for (int i = 0; i + 1 <= k; i++)
                    {
                        count[digit + 1, Less, i + 1] += (current - 1) * count[digit, MayExceed, i];
                    }
                }

                if (current >= 1)
                {
                    // 0
                    for (int i = 0; i <= k; i++)
                    {
                        count[digit + 1, Less, i] += count[digit, MayExceed, i];
                    }
                }

                // 超えない
                for (int i = 0; i + 1 <= k; i++)
                {
                    count[digit + 1, Less, i + 1] += 9 * count[digit, Less, i];
                }
                for (int i = 0; i <= k; i++)
                {
                    count[digit + 1, Less, i] += count[digit, Less, i];
                }
            }

            yield return count[n.Length, MayExceed, k] + count[n.Length, Less, k];
        }
    }
}


namespace Yorukatsu044
{
    class Program
    {
        static void Main(string[] args)
        {
            IAtCoderQuestion question = new QuestionE();    // 問題に合わせて書き換え
            var answers = question.Solve(Console.In);
            foreach (var answer in answers)
            {
                Console.WriteLine(answer);
            }
        }
    }
}

#region Base Classes

namespace Yorukatsu044.Questions
{

    public interface IAtCoderQuestion
    {
        IEnumerable<object> Solve(string input);
        IEnumerable<object> Solve(TextReader inputStream);
    }

    public abstract class AtCoderQuestionBase : IAtCoderQuestion
    {
        public IEnumerable<object> Solve(string input)
        {
            var stream = new MemoryStream(Encoding.Unicode.GetBytes(input));
            var reader = new StreamReader(stream, Encoding.Unicode);

            return Solve(reader);
        }

        public abstract IEnumerable<object> Solve(TextReader inputStream);
    }

}

#endregion

#region Extensions

namespace Yorukatsu044.Extensions
{
    internal static class TextReaderExtensions
    {
        internal static int ReadInt(this TextReader reader) => int.Parse(ReadString(reader));
        internal static long ReadLong(this TextReader reader) => long.Parse(ReadString(reader));
        internal static double ReadDouble(this TextReader reader) => double.Parse(ReadString(reader));
        internal static string ReadString(this TextReader reader) => reader.ReadLine();

        internal static int[] ReadIntArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(int.Parse).ToArray();
        internal static long[] ReadLongArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(long.Parse).ToArray();
        internal static double[] ReadDoubleArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(double.Parse).ToArray();
        internal static string[] ReadStringArray(this TextReader reader, char separator = ' ') => reader.ReadLine().Split(separator);
    }
}

#endregion

Measured memory_bytes: 13268