using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;

namespace AtCoder
{
    static class Program_D
    {
        class Solver
        {
            int ri => sc.Integer();
            long rl => sc.Long();
            double rd => sc.Double();
            string rs => sc.Scan();
            public StreamScanner sc = new StreamScanner(Console.OpenStandardInput());
            private List<long[]> scores;
            private int k;
            private int[] p;
            private int[] c;
            long allMax = -10000000000;

            public void Solve()
            {
                var n = ri;
                k = ri;
                p = new int[n];
                c = new int[n];
                for(int i = 0; i < n; ++i)
                {
                    p[i] = ri - 1;
                }
                for (int i = 0; i < n; ++i)
                {
                    c[i] = ri;
                }
                scores = new List<long[]>();
                for(int i = 0; i < n; ++i)
                {
                    if (p[i] == -1) continue;
                    scores.Add(CreateScores(i));
                }
                //DumpScores();
                //Wl("---");

                foreach (var score in scores)
                {
                    CalcMaxScore(score);
                }
                Wl(allMax);

            }

            private void CalcMaxScore(long[] score)
            {
                var work = new long[score.Length];
                int end = Math.Min(k, score.Length);
                var scoreSum = score.Sum();
                //Wl($"scoreSum[{scoreSum}]");

                long maxScore = -1;
                int maxIndex = -1;

                for(int t = 0; t < end; ++t)
                {
                    long wTmp = work[0];
                    for (int i = 0; i < score.Length; ++i)
                    {
                        var nextIndex = (i + 1) % score.Length;
                        var wTmp2 = work[nextIndex];
                        work[nextIndex] = wTmp + score[nextIndex];
                        wTmp = wTmp2;
                    }
                    //Wl(string.Join(" ", work.Select(tmp => tmp.ToString())));
                    var currentMax = work.Max();
                    //Wl(currentMax);
                    int nokoriLoop = (k - (t + 1)) / score.Length;
                    long maxScoreMod = currentMax;
                    if (scoreSum > 0)
                    {
                        //Wl($"add nokoriLoop[{nokoriLoop}] * scoreSum[{scoreSum}]");
                        maxScoreMod = currentMax + nokoriLoop * scoreSum;
                    }
                    if (t == 0 || maxScoreMod > maxScore)
                    {
                        maxScore = maxScoreMod;
                        maxIndex = t;
                    }
                }

                
                //Wl($"maxIndex[{maxIndex}] maxScore[{maxScore}] ");
                allMax = Math.Max(allMax, maxScore);
            }

            private void DumpScores()
            {
                foreach (var score in scores)
                {
                    Wl(string.Join(" ", score.Select(s => s.ToString())));
                }
            }

            long[] CreateScores(int index)
            {
                var result = new List<long>();
                do
                {
                    if (p[index] == -1) return result.ToArray();
                    result.Add(c[p[index]]);
                    var newIndex = p[index];
                    p[index] = -1;
                    index = newIndex;
                } while (true);
            }



            // ----------------------------------------------------------------------------
            static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }


            string Rl()
            {
                return Console.ReadLine();
            }
            void Wl(UInt64 val)
            {
                Console.WriteLine(val);
            }
            void Wl(Int64 val)
            {
                Console.WriteLine(val);
            }
            void Wl(uint val)
            {
                Console.WriteLine(val);
            }
            void Wl(int val)
            {
                Console.WriteLine(val);
            }
            void Wl(double val)
            {
                Console.WriteLine(val);
            }
            void Wl(string mes)
            {
                Console.WriteLine(mes);
            }
            public int Int()
            {
                return int.Parse(Console.ReadLine());
            }

            public int[] Ints(int subtract)
            {
                return Console.ReadLine().Split(' ').Select(s => int.Parse(s) - subtract).ToArray();
            }
            public Int64[] Int64s(Int64 subtract)
            {
                return Console.ReadLine().Split(' ').Select(s => Int64.Parse(s) - subtract).ToArray();
            }
            public UInt64[] UInt64s(UInt64 subtract)
            {
                return Console.ReadLine().Split(' ').Select(s => UInt64.Parse(s) - subtract).ToArray();
            }


        }



        static void Main(string[] args)
        {
            Console.SetOut(new Printer(Console.OpenStandardOutput()) { AutoFlush = false });
            new Solver().Solve();
            Console.Out.Flush();
        }
    }

    public class Printer : StreamWriter
    {
        public override IFormatProvider FormatProvider => CultureInfo.InvariantCulture;
        public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
    }

    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;

        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 != 0; b = (char)read()) if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long() { return isEof ? long.MinValue : long.Parse(Scan()); }
        public int Integer() { return isEof ? int.MinValue : int.Parse(Scan()); }
        public double Double() { return isEof ? double.NaN : double.Parse(Scan(), CultureInfo.InvariantCulture); }
    }

    struct ModInt
    {
        const int MOD = 1000000007;
        long Data;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public ModInt(long data) { if ((Data = data % MOD) < 0) Data += MOD; }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static implicit operator long(ModInt modInt) => modInt.Data;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static implicit operator ModInt(long val) => new ModInt(val);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator +(ModInt a, ModInt b)
        {
            long res = a.Data + b.Data;
            return new ModInt() { Data = res >= MOD ? res - MOD : res };
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator +(ModInt a, long b) => a.Data + b;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator -(ModInt a, ModInt b)
        {
            long res = a.Data - b.Data;
            return new ModInt() { Data = res < 0 ? res + MOD : res };
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator -(ModInt a, long b) => a.Data - b;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator *(ModInt a, ModInt b) => new ModInt() { Data = a.Data * b.Data % MOD };
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ModInt operator /(ModInt a, ModInt b) => a.Data * GetInverse(b);

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override string ToString() => Data.ToString();

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static long GetInverse(long a)
        {
            long div;
            long p = MOD;
            long x1 = 1, y1 = 0, x2 = 0, y2 = 1;
            while (true)
            {
                if (p == 1) return x2;
                div = a / p;
                x1 -= x2 * div;
                y1 -= y2 * div;
                a %= p;
                if (a == 1) return x1;
                div = p / a;
                x2 -= x1 * div;
                y2 -= y1 * div;
                p %= a;
            }
        }
    }

}


Measured memory_bytes: 28548