// #define _GLIBCXX_DEBUG
// #pragma GCC optimize ("trapv") // kills the program on integer overﬂows (but is really slow).
#include <bits/stdc++.h>
using namespace std;
using namespace std::chrono;

#define ll long long
#define ull unsigned long long
#define FIO ios_base::sync_with_stdio(false);cin.tie(NULL);
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define ff first
#define ss second
#define vt vector
#define vll vt<ll>
#define pll pair<ll,ll>
#define vpll vt<pll>
#define vvll vt<vll>
#define all(v) v.begin(),v.end()
#define FOR(i,n) for(ll i=0;i<n;i++)
#define ffo(i,a,b) for(ll i=a;i<=b;i++)
#define rfo(i,a,b) for(ll i=a;i>=b;i--)
#define space cout<<"\n\n";
#define endl "\n"
#define pqmx priority_queue<ll>
#define pqmn priority_queue<ll,vll,greater<ll>>
#define fps(x,y) fixed<<setprecision(y)<<x
#define merg(a,b,c) set_union(a.begin(),a.end(),b.begin(),b.end(),inserter(c,c.begin()))
#define set_ar(arr,v) memset(arr,v,sizeof(arr))
#define go_t int testcases; cin>>testcases; ffo(caseno,1,testcases)

#define ctime auto start = high_resolution_clock::now()
#define etime auto stop = high_resolution_clock::now()
#define ptime auto z1z = duration_cast<microseconds>(stop-start); cout<<"Time elapsed : "<<z1z.count()<<" microseconds\n"

#define dbg1(x)             cout <<#x<<": "<<x<<'\n';
#define dbg2(x, y)          cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<<'\n';
#define dbg3(x, y, z)       cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<'\n';
#define dbg4(a, b, c, d)    cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<'\n';
#define dbg5(a, b, c, d, e) cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<<": "<<e<<'\n';

const ll mod = 1e9 + 7;
const ll N = 5e3 + 6;
const ll maxN = 5e3 + 5;
const ll MAX_SIZE = 2e6 + 6;
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const double PI = 3.14159265359;

ll powerM(ll x, ll y, ll M = mod) { // default argument
	ll v = 1; x = x % M; while (y > 0) {if (y & 1)v = (v * x) % M; y = y >> 1; x = (x * x) % M;} return v;
}

ll power(ll x, ll y) {
	ll v = 1; while (y > 0) {if (y & 1)v = v * x; y = y >> 1; x = x * x;} return v;
}

vt<bool> vis(maxN, 0);
vvll adj(maxN);
vll p(maxN), c(maxN);

void dfs(ll node, ll par, ll& a1, vll& fthis) {
	vis[node] = 1;
	a1 += c[node];
	fthis.pb(a1);
	for (auto& u : adj[node]) {
		if (vis[u]) continue;
		// a1 += c[u];
		dfs(u, node, a1, fthis);
	}
	vis[node] = 0;
}

int main()
{
#ifndef ONLINE_JUDGE
	freopen("in4.txt", "r", stdin);
	freopen("out3.txt", "w", stdout);
#endif
	FIO
	ll n, k;
	cin >> n >> k;
	FOR(i, n) {
		cin >> p[i];
		adj[i].pb(p[i] - 1);
	}
	FOR(i, n) cin >> c[i];
	// FOR(i, n) {
	// 	for (auto& it : adj[i])
	// 		cout << it << " "; cout << endl;
	// }
	ll ans = -1e16;
	for (int i = 0; i < n; ++i) {
		// if (vis[i])
		// 	continue;
		ll temp = 0;
		ll a1 = 0;
		vll fthis;
		dfs(i, -1, a1, fthis);
		//
		ll sz = fthis.size();
		ll cycles = k / sz;
		if (cycles == 0) {
			for (int j = 0; j < min(k, sz); j++) {
				ans = max(ans, fthis[j]);
			}
		}
		else {
			for (int j = 0; j < sz; j++) {
				ans = max(ans, fthis[j]);
			}
			temp = (cycles - 1) * fthis.back();
			ll rem = k - ((cycles - 1) * sz);
			if (rem >= sz) {
				ll t2 = temp;
				for (int j = 0; j < sz; ++j) {
					t2 = temp + fthis[j];
					ans = max(t2, ans);
				}
				temp += fthis.back();
				ans = max(ans, temp);
				rem -= sz;
				t2 = temp;
				for (int j = 0; j < rem; ++j) {
					t2 = temp + fthis[j];
					ans = max(t2, ans);
				}
			}
			else {
				ll t2 = temp;
				for (int j = 0; j < rem; ++j) {
					t2 = temp + fthis[j];
					ans = max(t2, ans);
				}
			}
		}
	}
	cout << ans << endl;
	return 0;
}


Measured memory_bytes: 4424