#define _CRT_SECURE_NO_DEPRECATE
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
#include "bits/stdc++.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define int long long int
#define SYNC std::ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
#define FRE freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
typedef long double ld;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
typedef vector<ii>   vii;
//typedef tree<int, null_type, less<int>, rb_tree_tag, 
//             tree_order_statistics_node_update> 
//    ost;
#define rep(i,l,r)   for (int i = (l); i < (r); i++)
#define here cout << " Hey!!\n";
#define  pb push_back
#define  F  first
#define  S  second
#define all(v) (v).begin(),(v).end()
#define sz(a) (int)((a).size())
#define sq(x) ((x)*(x))
template <typename T>
void etch(T V) {
	for (auto x : V)	cout << x << ' ' ;
	cout << '\n';
}
vector<string> vec_splitter(string s) {
	s += ',';
	vector<string> res;
	while(!s.empty()) {
		res.push_back(s.substr(0, s.find(',')));
		s = s.substr(s.find(',') + 1);
	}
	return res;
}
void debug_out(
vector<string> __attribute__ ((unused)) args,
__attribute__ ((unused)) int idx, 
__attribute__ ((unused)) int LINE_NUM) { cerr << endl; } 
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
	if(idx > 0) cerr << ", "; else cerr << "Line(" << LINE_NUM << ") ";
	stringstream ss; ss << H;
	cerr << args[idx] << " = " << ss.str();
	debug_out(args, idx + 1, LINE_NUM, T...);
}
#ifndef ONLINE_JUDGE
#define debug(...) debug_out(vec_splitter(#__VA_ARGS__), 0, __LINE__, __VA_ARGS__)
#else
#define debug(...) 42
#endif
const int MOD = 1e9+7;
const int MOD1 = 998244353;
const int N = 2e5+5;
const int INF = 1000111000111000111LL;
const ld EPS = 1e-12;
const ld PI = 3.141592653589793116;

int32_t main()
{
	SYNC
	int n, k; cin >> n >> k;
	vi p(n), c(n);
	rep(i,0,n)	cin >> p[i], p[i]--;
	rep(i,0,n)	cin >> c[i];
	vi vis(n,0);
	int ans = -INF;
	rep(i,0,n) {
		if (vis[i])	continue;
		vi curCycle;
		curCycle.pb(i);
		vis[i] = 1;
		int curNode = p[i];
		while (curNode != i) {
			curCycle.pb(curNode);
			vis[curNode] = 1;
			curNode = p[curNode];
		}
		for (auto &x : curCycle)
			x = c[x];
		int sumAll = 0;
		rep(i,0,sz(curCycle))	sumAll += curCycle[i];
		if (k <= sz(curCycle)) {
			int res = curCycle[0];
			int len = sz(curCycle);
			rep(j,0,len) {
				int curSum = 0;
				int moves = k;
				for (int node = j; moves > 0 ; node++, moves--) {
					curSum += curCycle[node%len];
					res = max(res, curSum);
				}
			}
			ans = max(ans, res);
			continue;	
		} else {
			int res = curCycle[0];
			int len = sz(curCycle);
			rep(j,0,len) {
				int curSum = 0;
				int moves = len;
				for (int node = j; moves > 0; node++, moves--) {
					curSum += curCycle[node%len];
					res = max(res, curSum);
				}
				moves = len + k%len;
				curSum = sumAll* (k/len - 1);
				res = max(res, curSum);
				for (int node = j; moves > 0 ; node++, moves--) {
					curSum += curCycle[node%len];
					res = max(res, curSum);
				}
			}
			ans = max(ans, res);
		}
	}
	cout << ans;
	return 0;
}

Measured memory_bytes: 3820