class Program
{
    static void Main()
    {
        int[] nk = Console.ReadLine().Split().Select(_ => int.Parse(_)).ToArray();
        int N = nk[0];
        int K = nk[1];
        long[] A = Console.ReadLine().Split().Select(_ => long.Parse(_)).ToArray();

        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");
    }
}