#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <climits>
#include <cstring>
#include <cassert>


using namespace std;
#define SZ(x) (int)(x.size())
#define REP(i, n) for(int i=0;i<n;++i)
#define FOR(i, a, b) for(int i=a;i<b;++i)
#define RREP(i, n) for(int i=n-1;i>=0;--i)
#define RFOR(i, a, b) for(int i=b-1;i>=a;--i)

#define all(x) begin(x),end(x)
#define dump(x) cerr<<#x<<" = "<<(x)<<endl
#define debug(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;
const double eps = 1e-8;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}


template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> p) {
    os << p.first << ":" << p.second;
    return os;
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T1, class T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
    os << "[";
    for (auto it = mp.begin(); it != mp.end(); ++it) {
        if (it != mp.begin()) {
            os << ", ";
        }
        os << *it;
    }
    return os << "]";
}


// edit
struct Solve {
    int N, K;
    vector<ll> cscore;
    vector<int> csize;
    vector<bool> visit;
    vector<int> P;
    vector<ll> C;

    void dfs(int v, int &sz, ll &score) {
        if (visit[v]) {
            // TODO
            return;
        }

        visit[v] = true;
        sz++;
        score += C[v];
        dfs(P[v], sz, score);

        csize[v] = sz;
        cscore[v] = score;
    }

    ll dfs2(int v, int sz) {
        if (sz == 0) {
            return 0ll;
        }
        ll ret = max(0ll, dfs2(P[v], sz - 1)) + C[P[v]];
        return ret;
    }

    void solve() {
        cin >> N >> K;
        cscore.resize(N, -1);
        csize.resize(N, -1);
        visit.resize(N, false);
        P.resize(N);
        C.resize(N);

        REP(i, N) cin >> P[i];
        REP(i, N) P[i]--;
        REP(i, N) cin >> C[i];

        REP(i, N) {
            int sz = 0;
            ll score = 0;
            if (!visit[i]) dfs(i, sz, score);
        }

        ll ans = -LINF;

        for (int i = 0; i < N; ++i) {
            if (cscore[i] <= 0) {
                ll score = 0;
                ll add = dfs2(i, min(N, K));
                score += add;
                chmax(ans, score);
            } else {
                ll div = max((ll) K / csize[i] - 1, 0ll);
                ll score = div * cscore[i];
                ll nokori = K - div * csize[i];
                ll add = dfs2(i, nokori);
                score += add;
                chmax(ans, score);
            }
        }

        cout << ans << endl;


    }
};

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
//    std::ifstream in("input.txt");
//    std::cin.rdbuf(in.rdbuf());

    Solve().solve();


    return 0;
}


Measured memory_bytes: 3620