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

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 a = NList;
        Array.Sort(a, (l, r) => r.CompareTo(l));
        var ans = int.MinValue;
        var sum = 0;
        for (var i = 0; i < k; ++i)
        {
            sum += a[i];
            ans = Math.Max(ans, sum);
        }
        WriteLine(ans);
    }
}