using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("5 2");
            WillReturn.Add("10 20 30 40 50");
            //80
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("4 3");
            WillReturn.Add("-10 -20 100 100");
            //Impossible
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("4 2");
            WillReturn.Add("-10 -20 100 100");
            //90
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static long[] GetSplitArr(string pStr)
    {
        return (pStr == "" ? new string[0] : pStr.Split(' ')).Select(pX => long.Parse(pX)).ToArray();
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long[] wkArr = GetSplitArr(InputList[0]);
        long K = wkArr[1];

        long[] AArr = GetSplitArr(InputList[1]);

        // 最大スコア[消した数 , 次に消せるか]なDP表
        long?[,] PrevDP = new long?[K + 1, 2];
        PrevDP[0, 1] = 0;

        foreach (long EachA in AArr) {
            long?[,] CurrDP = new long?[K + 1, 2];

            for (long I = 0; I <= K; I++) {
                for (long J = 0; J <= 1; J++) {
                    if (PrevDP[I, J].HasValue == false) continue;

                    Action<long, long, long> UpdateAct = (pNewI, pNewJ, pNewVal) =>
                    {
                        if (pNewI > K) return;

                        if (CurrDP[pNewI, pNewJ].HasValue) {
                            if (CurrDP[pNewI, pNewJ].Value >= pNewVal) {
                                return;
                            }
                        }
                        CurrDP[pNewI, pNewJ] = pNewVal;
                    };

                    // 消す遷移
                    if (J == 1) {
                        UpdateAct(I + 1, 0, PrevDP[I, J].Value + EachA);
                    }

                    // 消さない遷移
                    UpdateAct(I, 1, PrevDP[I, J].Value);
                }
            }
            PrevDP = CurrDP;
        }

        var AnswerList = new List<long>();
        for (long J = 0; J <= 1; J++) {
            if (PrevDP[K, J].HasValue) {
                AnswerList.Add(PrevDP[K, J].Value);
            }
        }

        if (AnswerList.Count == 0) {
            Console.WriteLine("Impossible");
        }
        else {
            Console.WriteLine(AnswerList.Max());
        }
    }
}