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// #pragma GCC optimize(2)
// #pragma GCC optimize(3)
// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
// #pragma GCC target("avx,avx2,fma")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double lld;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> ppl;
#define ain(a,n) for(ll i=0;i<(n);++i)	cin>>(a)[i];
#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
#define loop(i,n) for(ll i=0;i<(n);++i)
#define FOR(i,a,b) for(ll i=(a);i<=(b);++i)
#define FORD(i,a,b) for(ll i=(a);i>=(b);--i)
#define cases ll T=0;cin>>T;while(T--)
#define ff first
#define ss second
#define all(v) v.begin(),v.end()
#define END "\n"
#define pb push_back
#define mp make_pair
#define go(c,itr) for(auto itr=(c).begin(); itr!=(c).end(); ++itr)
// #define back(c,itr) for(auto itr=(c).rbegin(); itr!=(c).rend(); ++itr)
#define PI 3.14159265359
#define inf 9e18
#define MOD 1000000007
#define MODU 998244353
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define MAXN 100005
#define BLOCK 555
const string alpha = "abcdefghijklmnopqrstuvwxyz";
const ll N = 200005;
const long double epsilon = 1e-9;
inline ll myceil(ll a, ll b) { if (a % b == 0)	return (a / b);	return (a / b + 1);}
ll binexp(ll a, ll b, ll m) {
	a %= m;
	ll res = 1;
	while (b > 0) {
		if (b & 1)
			res = res * a % m;
		a = a * a % m;
		b >>= 1;
	}
	return res;
}
ll modinvfermat(ll a, ll m)
{
	return binexp(a, m - 2, m);
}
void task(bool flag)
{
	if (flag)
		cout << "YES\n";
	else
		cout << "NO\n";
}
ll lcm(ll a, ll b)
{
	return ((1LL * a * b) / (__gcd(a, b)));
}

signed main() {
// #ifndef ONLINE_JUDGE
// 	freopen("input.txt", "r", stdin);
// 	freopen("output.txt", "w", stdout);
// #endif
	fast
	ll n, k;
	cin >> n >> k;
	vl p(n + 1);
	FOR(i, 1, n)	cin >> p[i];
	vl cost(n + 1);
	FOR(i, 1, n)	cin >> cost[i];
	ll ans = -inf;
	FOR(i, 1, n)
	{
		ll curr = 0, cum = 0, ind = p[i];
		vl temp;
		while (ind != i)
		{
			// cerr << i << " " << ind << END;
			temp.pb(cost[ind]);
			ind = p[ind];
		}
		temp.pb(cost[ind]);
		ll len = temp.size();
		vl pref(len, 0);
		pref[0] = temp[0];
		FOR(j, 1, len - 1)	pref[j] = pref[j - 1] + temp[j];
		curr = pref[0];
		loop(j, min(k, len))
		{
			curr = max(curr, pref[j]);
		}
		if (k > len)
		{
			loop(j, k % len)
			{
				cum = max(cum, pref[j]);
			}
			ll cum2 = 0;
			loop(j, len)
			{
				cum2 = max(cum2, pref[j]);
			}
			curr = max(curr, max(cum + 1LL * pref.back() * (k / len), pref.back() * (k / len - 1) + cum2));
		}
		ans = max(ans, curr);
	}
	cout << ans << END;



// #ifndef ONLINE_JUDGE
// 	cout << "\nTime Elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " sec\n";
// #endif
	return 0;
}

Measured memory_bytes: 3844