import java.util.ArrayList;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

public class Main {
    InputStream is;

    int __t__ = 1;
    int __f__ = 0;
    int __FILE_DEBUG_FLAG__ = __f__;
    String __DEBUG_FILE_NAME__ = "src/main/java/D5";

    FastScanner in;
    PrintWriter out;

    boolean[] vis;
    public void solve() {
        int n = in.nextInt();
        long k = in.nextLong();
        int[] p = new int[n];
        for (int i = 0; i < n; i++) {
            p[i] = in.nextInt() - 1;
        }
        long[] c = in.nextLongArray(n);

        vis = new boolean[n];
        long res = Long.MIN_VALUE;
        for (int i = 0; i < n; i++) {
            res = Math.max(res, dfs(i, i, k, p, c, new ArrayList<>()));
        }
        System.out.println(res);
    }

    private long dfs(int u, int root, long k, int[] p, long[] c, ArrayList<Long> list) {
        list.add(c[u]);
        if (p[u] == root) {
            int m = list.size();
            long[] sum = new long[m+1];
            long res = list.get(0);
            for (int i = 0; i < m; i++) {
                sum[i+1] = sum[i] + list.get(i);
                if (i < k) {
                    res = Math.max(res, sum[i+1]);
                }
            }
            for (int i = 0; i < m; i++) {
                if (k / m > 1) {
                    res = Math.max(res, sum[m] * (k / m - 1) + sum[i+1]);
                }
            }
            res = Math.max(sum[m] * k / m, res);
            for (int i = 0; i < m; i++) {
                if (k / m > 0 && i < k % m) {
                    res = Math.max(res, sum[m] * (k / m) + sum[i+1]);
                }
            }
            return res;
        } else {
            return dfs(p[u], root, k, p, c, list);
        }
    }

    public void run() {
        if (__FILE_DEBUG_FLAG__ == __t__) {
            try {
                is = new FileInputStream(__DEBUG_FILE_NAME__);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            System.out.println("FILE_INPUT!");
        } else {
            is = System.in;
        }
        in = new FastScanner(is);
        out = new PrintWriter(System.out);

        solve();
    }

    public static void main(final String[] args) {
        new Main().run();
    }
}


class FastScanner {
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;

    public FastScanner(InputStream stream) {
        this.stream = stream;
        // stream = new FileInputStream(new File("dec.in"));
    }

    int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public boolean isSpaceChar(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    public boolean isEndline(int c) {
        return c == '\n' || c == '\r' || c == -1;
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public int[] nextIntArray(int n) {
        int[] array = new int[n];
        for (int i = 0; i < n; i++)
            array[i] = nextInt();

        return array;
    }

    public int[][] nextIntMap(int n, int m) {
        int[][] map = new int[n][m];
        for (int i = 0; i < n; i++) {
            map[i] = nextIntArray(m);
        }
        return map;
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public long[] nextLongArray(int n) {
        long[] array = new long[n];
        for (int i = 0; i < n; i++)
            array[i] = nextLong();

        return array;
    }

    public long[][] nextLongMap(int n, int m) {
        long[][] map = new long[n][m];
        for (int i = 0; i < n; i++) {
            map[i] = nextLongArray(m);
        }
        return map;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public double[] nextDoubleArray(int n) {
        double[] array = new double[n];
        for (int i = 0; i < n; i++)
            array[i] = nextDouble();

        return array;
    }

    public double[][] nextDoubleMap(int n, int m) {
        double[][] map = new double[n][m];
        for (int i = 0; i < n; i++) {
            map[i] = nextDoubleArray(m);
        }
        return map;
    }

    public String next() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }

    public String[] nextStringArray(int n) {
        String[] array = new String[n];
        for (int i = 0; i < n; i++)
            array[i] = next();

        return array;
    }

    public String nextLine() {
        int c = read();
        while (isEndline(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do {
            res.appendCodePoint(c);
            c = read();
        } while (!isEndline(c));
        return res.toString();
    }

    public int[][] nextPackedIntArrays(int packN, int size) {
        int[][] res = new int[packN][size];
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < packN; j++) {
                res[j][i] = nextInt();
            }
        }
        return res;
    }
}


Measured memory_bytes: 57260