class Program
{
    static (int a, int b) GetInput2()
    {
        int[] input = Console.ReadLine().Split().Select(_ => int.Parse(_)).ToArray();
        return (input[0], input[1]);
    }

    static void Main()
    {
        (int N, int K) = GetInput2();
        int[] A = Console.ReadLine().Split().Select(_ => int.Parse(_)).ToArray();

        void ArrayFill(long[,] arr)
        {
            for (int i = 0; i < arr.GetLength(0); i++)
            {
                for (int j = 0; j < arr.GetLength(1); j++)
                    arr[i, j] = long.MinValue; // long.MinValue は値が未定義であることを示す
            }
        }

        long[,] dp = new long[K + 1, 2];
        ArrayFill(dp);
        dp[0, 0] = 0;

        foreach (long v in A)
        {
            long[,] new_dp = new long[K + 1, 2];
            ArrayFill(new_dp);

            for (int k = 0; k <= K; k++)
            {
                if(dp[k, 0] != long.MinValue && k + 1 <= K)
                    new_dp[k + 1, 1] = dp[k, 0] + v;

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