class Program
{
    static void Main(string[] args)
    {
        string[] topInput = Console.ReadLine()!.Split(' ');
        int total = int.Parse(topInput[1]);
        string[] bottomInput = Console.ReadLine()!.Split(" ");
        List<int> numList = new List<int>();

        for (int i = 0; i < bottomInput.Length; i++)
        {
            numList.Add(int.Parse(bottomInput[i]));
        }
        numList.Sort();

        int max = numList[numList.Count - 1];
        for (int i = 1;i < total;i++)
        {
            if (max < max + numList[numList.Count - 1 - i])
            {
                max = max + numList[numList.Count - 1 - i];
            }
        }
        Console.WriteLine(max);
    }
}