using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using static System.Console;
using static System.Math;

class program
{
    static public int mod = 1000000007;
    static void Main()
    {
        var nk = inta();
        int n = nk[0], k = nk[1];
        var p = inta();
        var isp = new bool[n];
        var c = inta();
        var roopsum = new List<long>();
        var roopct = new List<int>();
        var roop = new List<List<int>>();
        roop.Add(new List<int>());
        var roopmx = new List<List<long>>();
        roopmx.Add(new List<long>());
        int ct = 0;
        for(int i = 0; i < n; i++)
            if (!isp[i])
            {
                long sum = 0;
                var pre = i;
                var mx = int.MinValue;
                roopmx.Add(new List<long>());
                roopmx[ct].Add(0);
                roop.Add(new List<int>());
                for (int j = 0; j <= n; j++)
                {
                    pre = p[pre] - 1;
                    if (isp[pre])
                    {
                        roopmx[ct].Add(mx);
                        roopsum.Add(sum);
                        roopct.Add(j);
                        break;
                    }
                    else
                    {
                        isp[pre] = true;
                        roop[ct].Add(c[pre]);
                        sum += c[pre];
                        mx = Max(mx, c[pre]);
                    }
                }
                ct++;
            }

        for(int i = 0; i < ct; i++)
        {
            for (int j = 1; j < roopct[i]; j++)
                roopmx[i].Add(roopmx[i][1]);

            for (int j = 0; j < roopct[i]; j++)
                if (roop[i][j] > 0)
                {
                    long sum = roop[i][j];
                    for (int h = 1; h < roopct[i]; h++)
                    {
                        int hj = h + j;
                        sum += hj < roopct[i] ? roop[i][hj] : roop[i][hj - roopct[i]];
                        if (sum > roopmx[i][h+1]) roopmx[i][h+1] = sum;
                        if (roopmx[i][h] > roopmx[i][h+1]) roopmx[i][h+1] = roopmx[i][h];
                    }
                }
        }
        long ans = long.MinValue;
        for(int i = 0; i < ct; i++)
        {
            if(roopsum[i] > 0)
            {
                ans = Max(ans,(k / roopct[i]) * roopsum[i] + roopmx[i][k % roopct[i]]);
                if (k > roopct[i])
                    ans = Max(ans,((k / roopct[i]) - 1) * roopsum[i] + roopmx[i][roopct[i]]);
            }
            else
            {
                if(k > roopct[i])
                    ans = Max(ans, roopmx[i][roopct[i]]);
                else
                    ans = Max(ans, roopmx[i][k]);
            }
        }
        WriteLine(ans);
    }

    static int pow(int a, int b) { string binary = Convert.ToString(b, 2); int bileng = binary.Length; long a_power = a; long value = 1; for (int i = bileng - 1; i >= 0; i--) { if (binary[i] == '1') { value = value * a_power % mod; } a_power = a_power * a_power % mod; } return (int)value; }
    static string rstr() { return ReadLine(); }
    static int rint() { return int.Parse(ReadLine()); }
    static long rlong() { return long.Parse(ReadLine()); }
    static string[] stra() { return ReadLine().Split(' '); }
    static char[] chara() { string[] a = stra(); string b = ""; for (int i = 0; i < a.Length; i++) { b += a[i]; } return b.ToCharArray(); }
    static int[] inta() { string[] read_str_array = ReadLine().Split(' '); int[] return_int_array = new int[read_str_array.Length]; for (int countup_i = 0; countup_i < read_str_array.Length; countup_i++) { return_int_array[countup_i] = int.Parse(read_str_array[countup_i]); } return return_int_array; }
    static long[] longa() { string[] read_str_array = ReadLine().Split(' '); long[] return_long_array = new long[read_str_array.Length]; for (long countup_i = 0; countup_i < read_str_array.Length; countup_i++) { return_long_array[countup_i] = long.Parse(read_str_array[countup_i]); } return return_long_array; }
    static double[] doublea() { string[] read_str_array = ReadLine().Split(' '); double[] return_double_array = new double[read_str_array.Length]; for (long countup_i = 0; countup_i < read_str_array.Length; countup_i++) { return_double_array[countup_i] = double.Parse(read_str_array[countup_i]); } return return_double_array; }
    static long GCD(long a, long b) { if (a < b) { long temp = a; a = b; b = temp; } if (a % b == 0) { return b; } else { long temp = b; b = a % b; a = temp; return GCD(a, b); } }
    static long LCM(long a, long b) { return a * b / GCD(a, b); }
    static void WriteArray2(int[,] a, int b, int c) { for (int i = 0; i < b; i++) { for (int j = 0; j < c; j++) { if (j != 0) Write(" "); Write(a[i, j]); } WriteLine(); } }
    static void WriteArray(int[] a, int b) { for (int i = 0; i < b; i++) { Write(" "); Write(a[i]); } WriteLine(); }
}


Measured memory_bytes: 29220