using System;
using System.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Number = System.Int64;
namespace Program
{

    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var m = sc.Integer();
            if (m <= 1)
            {
                IO.Printer.Out.WriteLine(0); return;
            }
            var a = new int[2 * n + 1];
            for (int i = 0; i < n; i++)
            {
                a[i + 1] = a[i + n + 1] = sc.Integer();
            }
            //otaku is god
            //dp[migi,kosuu,hidarihasi is zero, migihasi tukatta]
            var dp = new int[n + 1, m + 1, 2, 2];
            for (int i = 0; i <= n; i++)
            {
                for (int j = 0; j <= m; j++)
                {
                    for (int k = 0; k < 2; k++)
                        for (int l = 0; l < 2; l++)
                            dp[i, j, k, l] = -1000000000;
                }
            }
            dp[0, 0, 0, 0] = 0;
            dp[0, 1, 1, 1] = 0;
            var mk = 1;
            for (int i = 1; i < n; i++)
            {
                for (int j = 0; j <= mk; j++)
                {
                    for (int k = 0; k < 2; k++)
                    {
                        for (int l = 0; l < 2; l++)
                        {
                            if (dp[i - 1, j, k, l] <= -100000000) continue;
                            if (l == 1)
                            {
                                dp[i, j + 1, k, 1] = Math.Max(dp[i, j + 1, k, 1], dp[i - 1, j, k, l] + a[i]);
                                dp[i, j, k, 0] = Math.Max(dp[i, j, k, 0], dp[i - 1, j, k, l]);
                            }
                            else
                            {
                                dp[i, j + 1, k, 1] = Math.Max(dp[i, j + 1, k, 1], dp[i - 1, j, k, 0]);
                                dp[i, j, k, 0] = Math.Max(dp[i, j, k, 0], dp[i - 1, j, k, l]);
                            }


                        }
                    }
                }
                mk = Math.Min(mk + 1, m - 1);
            }
            var max = -10000000000;
            for (int i = 0; i < n; i++)
            {
                for (int k = 0; k < 2; k++)
                {
                    for (int l = 0; l < 2; l++)
                    {
                        var v = dp[i, m, k, l];
                        if (i == n - 1 && k == 1 && l == 1)
                            v += a[n];

                        max = Math.Max(max, v);
                    }
                }
            }
            IO.Printer.Out.WriteLine(max);

        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        Debug.Listeners.Add(new TextWriterTraceListener(Program.IO.Printer.Out));
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(Scan(), CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion

#region DisjointSet
public class DisjointSet
{
    public int[] par, ranks, count;
    public DisjointSet(int n)
    {
        par = new int[n];
        count = new int[n];
        for (int i = 0; i < n; i++)
        {
            par[i] = i;
            count[i] = 1;
        }
        ranks = new int[n];
    }
    public int this[int id] { get { return (par[id] == id) ? id : this[par[id]]; } }
    public bool Unite(int x, int y)
    {
        x = this[x]; y = this[y];
        if (x == y) return false;
        if (ranks[x] < ranks[y])
        {
            par[x] = y;
            count[y] += count[x];
        }
        else
        {
            par[y] = x;
            count[x] += count[y];
            if (ranks[x] == ranks[y])
                ranks[x]++;
        }
        return true;
    }
    public int Size(int x) { return count[this[x]]; }
    public bool IsUnited(int x, int y) { return this[x] == this[y]; }

}
#endregion
#region SegTree
[System.Diagnostics.DebuggerDisplay("Data={ToString()}")]
public class SegmentTree
{
    const long Max = -1000000000;
    int n;
    long[] data;
    public SegmentTree(int size)
    {
        n = 1;
        while (n < size)
            n <<= 1;
        data = new long[n << 1];
        for (int i = 0; i < data.Length; i++)
            data[i] = Max;
    }

    // turn kth index value into v
    public void Update(int k, long v)
    {
        k += n;
        if (data[k] > v) return;
        data[k] = v;
        k >>= 1;
        while (k > 0)
        {
            data[k] = Math.Max(data[k << 1], data[(k << 1) + 1]);
            k >>= 1;
        }

    }
    public long Query(int a, int b) { return Query(a, b, 1, 0, n); }
    private long Query(int a, int b, int k, int l, int r)
    {
        if (r <= a || b <= l)
            return Max;
        if (a <= l && r <= b)
            return data[k];
        else
        {
            var vl = Query(a, b, k << 1, l, (l + r) >> 1);
            var vr = Query(a, b, (k << 1) + 1, (l + r) >> 1, r);
            return Math.Max(vl, vr);
        }
    }

    /*
    ///<summary>Data[i]</summary>>
    public long this[int i] { get { return data[i + n]; } }
    ///<summary>Minimum[a,b)</summary>>
    public long this[int l, int r] { get { return Query(l, r, 1, 0, n); } }
    public override string ToString()
    {
        return string.Join(",", Enumerable.Range(0, n).Select(i => this[i]).Where(v => v != Max));
    }
    public string Visualize()
    {
        var sb = new System.Text.StringBuilder();
        var k = 2;
        var len = n << 1;
        for (int i = 1; i < len; i++)
        {
            if (data[i] != Max) sb.Append(data[i]);
            else sb.Append('-');
            if (i < k - 1) sb.Append(',');
            else if (i < len - 1)
            {
                sb.AppendLine();
                k <<= 1;
            }
        }
        return sb.ToString();
    }
     //*/
}
#endregion