using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, k) = (c[0], c[1]);
        var s = ReadLine();
        if (n - k == 1)
        {
            WriteLine(Up(s));
            return;
        }
        var n1 = Up(s);
        var n2 = Up(n1);
        if ((n - k) % 2 == 0)
        {
            WriteLine(string.Concat(n2.Skip((n - k) / 2 - 1).Take(k)));
        }
        else
        {
            WriteLine(string.Concat(n1.Skip((n - k) / 2).Take(k)));
        }
    }
    static string Up(string s)
    {
        var c = new List<char>();
        for (var i = 0; i + 1 < s.Length; ++i) c.Add(s[i] == '1' && s[i + 1] == '1' ? '0' : '1');
        return string.Concat(c);
    }
}