using System.Diagnostics;
class Program
{
    static string ReadLine() => Console.ReadLine().Trim();
    static int ReadInt() => int.Parse(ReadLine());
    static long ReadLong() => long.Parse(ReadLine());
    static int[] ReadIntArray() { string str = ReadLine(); return str != "" ? str.Split().Select(_ => int.Parse(_)).ToArray() : new int[0]; }
    static long[] ReadLongArray() { string str = ReadLine(); return str != "" ? str.Split().Select(_ => long.Parse(_)).ToArray() : new long[0]; }
    static (int, int) ReadInt2() { int[] vs = ReadIntArray(); return (vs[0], vs[1]); }
    static (int, int, int) ReadInt3() { int[] vs = ReadIntArray(); return (vs[0], vs[1], vs[2]); }
    static (int, int, int, int) ReadInt4() { int[] vs = ReadIntArray(); return (vs[0], vs[1], vs[2], vs[3]); }
    static (int, int, int, int, int) ReadInt5() { int[] vs = ReadIntArray(); return (vs[0], vs[1], vs[2], vs[3], vs[4]); }
    static (long, long) ReadLong2() { long[] vs = ReadLongArray(); return (vs[0], vs[1]); }
    static (long, long, long) ReadLong3() { long[] vs = ReadLongArray(); return (vs[0], vs[1], vs[2]); }
    static (long, long, long, long) ReadLong4() { long[] vs = ReadLongArray(); return (vs[0], vs[1], vs[2], vs[3]); }

    static void Main()
    {
        SourceExpander.Expander.Expand();

        (int N, int K) = ReadInt2();
        long[] A = ReadLongArray();

        long[,] dp = new long[K + 1, 2];
        for (int i = 0; i < K + 1; i++)
        {
            dp[i, 0] = long.MinValue;
            dp[i, 1] = long.MinValue;
        }

        dp[0, 0] = 0;

        for (int i = 0; i < N; i++)
        {
            long v = A[i];

            long[,] n_dp = (long[,])dp.Clone();
            for (int j = 0; j <= K; j++)
            {
                if (dp[j, 0] != long.MinValue)
                {
                    if (j + 1 <= K && n_dp[j + 1, 1] < dp[j, 0] + v)
                        n_dp[j + 1, 1] = dp[j, 0] + v;
                }
                if (dp[j, 1] != long.MinValue)
                {
                    if (n_dp[j, 0] < dp[j, 1])
                        n_dp[j, 0] = dp[j, 1];
                }
            }
            dp = n_dp;
        }

        long ans = Math.Max(dp[K, 0], dp[K, 1]);
        if(ans > long.MinValue)
            Console.WriteLine(ans);
        else
            Console.WriteLine("Impossible");
    }

    void F11()
    {
        (int N, int K) = ReadInt2();
        long[] A = ReadLongArray();

        long[] dp = new long[K + 1];

        for (int i = 0; i < N; i++)
        {
            long v = A[i];

            long[] n_dp = (long[])dp.Clone();
            for (int j = 0; j <= K; j++)
            {
                if (j + 1 <= K && n_dp[j + 1] < dp[j] + v)
                    n_dp[j + 1] = dp[j] + v;
                if (n_dp[j] < dp[j])
                    n_dp[j] = dp[j];
            }
            dp = n_dp;
        }
        //Console.WriteLine(dp.Max());
    }
}
#region Expanded by https://github.com/kzrnm/SourceExpander
namespace SourceExpander{public class Expander{[Conditional("EXP")]public static void Expand(string inputFilePath=null,string outputFilePath=null,bool ignoreAnyError=true){}public static string ExpandString(string inputFilePath=null,bool ignoreAnyError=true){return "";}}}
#endregion Expanded by https://github.com/kzrnm/SourceExpander