#include <iostream>
#include <cmath>
#include <iomanip>
#include <vector>
#include <stack>
#include <queue>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <iterator>
#include <unordered_map>
#include <unordered_set>
#include <sstream>
#include <fstream>
#include <tuple>

using namespace std;

#define fori(t) for(int i = 0; i < t; ++i)
#define forj(n) for(int j = 0; j < n; ++j)
#define fork(n) for(int k = 0; k < n; ++k)
#define forai(a) for(auto& i : a)
#define foraj(a) for(auto& j : a)
#define forak(a) for(auto& k : a)
#define forp(s, n, d) for(int p = s; p < n; p += d)
#define fast cin.tie(0); cout.tie(0); std::ios_base::sync_with_stdio(0);
#define pb(a) push_back(a);
#define pob(a) pop_back(a);
#define sorti(a) sort(a.begin(), a.end());
#define sortm(a, n) sort(a, a + n);
#define reversi(a) reverse(a.begin(), a.end());
#define fi first
#define se second
#define yes cout << "Yes\n";
#define no cout << "No\n";
#define ans(a) cout << a << '\n';
#define res(a, n) a.resize(n);
#define read(a, n) a.resize(n); fori(n) cin >> a[i];
#define int long long
//#define double long double

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef pair<long long, long long> llll;
typedef vector<int> vi;
typedef vector<long long> vll;
typedef vector<pair<int, int>> vii;
typedef vector<pair<int, pair<int, int>>> viii;
typedef pair<int, pair<int, int>> iii;
typedef vector<pair<long long, long long>> vllll;
typedef vector<vector<int>> vvi;
typedef vector<vector<ll>> vvll;
typedef vector<bool> vb;
typedef pair<char, char> cc;
typedef pair<pair<char, char>, char> ccc;
typedef vector<char> vc;
typedef pair<int, char> ic;
typedef pair<ii, char> iic;
typedef vector<bool> vb;
typedef set<int> si;
typedef set<ii> sii;
typedef unsigned long long ull;
typedef pair<ull, ull> ullll;
typedef pair<double, double> dd;
typedef vector<dd> vdd;
typedef vector<pair<ull, ull>> vullll;
typedef pair<bool, bool> bb;
typedef vector<bb> vbb;
typedef vector<vector<ii>> vvii;
typedef vector<vector<iii>> vviii;

const int INF = 2147483647;
const ll LONGINF = 9223372036854775807;
const ll MOD = 1e9 + 7;

vi p, c;

void solve()
{
    int n, k;
    cin >> n >> k;
    read(p, n)
    forai(p) --i;
    read(c, n)
    ll maxRes = -LONGINF;
    fori(n)
    {
        ll sum = 0;
        int counter = i, col = 0;
        do
        {
            sum += c[counter];
            counter = p[counter];
            ++col;
        } while (counter != i);
        if (sum <= 0 || k <= col)
        {
            int ops = min(k, col), counter = i;
            ll sum = 0;
            while (ops > 0)
            {
                sum += c[counter];
                counter = p[counter];
                --ops;
                maxRes = max(maxRes, sum);
            }
        }
        else
        {
            ll suma = ((k + col - 1) / col - 2) * sum;
            ll ops = k - ((k + col - 1) / col - 2) * col;
            int counter = i;
            if (ops != k) maxRes = max(maxRes, suma);
            while (ops > 0)
            {
                suma += c[counter];
                counter = p[counter];
                --ops;
                maxRes = max(maxRes, suma);
            }
        }
    }
    ans(maxRes)
}

signed main()
{
    fast
    bool mult = false;
    if (mult)
    {
        int t;
        cin >> t;
        while (t--) solve();
    }
    else solve();
    return 0;
}


Measured memory_bytes: 3220