#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag,tree_order_statistics_node_update>   
using namespace std;
using namespace __gnu_pbds;
typedef long long ll; 
#define int long long
typedef unsigned long long lu;
typedef vector<ll> v;
typedef vector<vector<ll> > vv;
typedef vector<string>  vs;
typedef vector<pair<ll,ll>> vpr;
typedef vector<bool>vb;
typedef vector<double>vd;
typedef long double ld;
#define f(i,n) for(ll i = 0; i < n; i++)
#define ff(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define endl "\n"
#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define amax(x,y) if(y>x) x=y;
#define amin(x,y) if(y<x)x=y;
#define bg(x) x.begin()
#define sz(x) (ll)x.size()
#define in(x,n) for(ll i=0;i<n;i++)cin>>x[i]
#define out(x,n) for(ll i=0;i<n;i++)cout<<x[i]<<" " 
#define mxt(a) *(max_element(a.begin(),a.end()))
#define mnt(a) *(min_element(a.begin(),a.end())
#define tc ll t;cin>>t;while(t--)
typedef pair<ll,ll> pi;
#define yes cout<<"YES\n";
#define no cout<<"NO\n";
#define yesno(f) if(f) yes else no
const v dx = {1, -1, 0, 0};
const v dy = {0, 0, 1, -1};
const ld PI = 2 * acos(0.0);
ll cel(ll x1,ll y1){if((x1%y1)==0)return x1/y1;else return x1/y1+1;}
ll power(ll a,ll b,ll m)
{
    if(b==0)
        return 1;
    ll d=power(a,b/2,m);
    d=(d*d)%m;
    if(b&1)
        d=(d*a)%m;
    return d;
}
const ll mod=1e9+7;
int MOD(int a)
{
    if(a<0)
        a+=mod;
    if(a>=mod)
        a%=mod;
    return a;
}
// set_name.find_by_order(k) It returns to an iterator to the kth element (counting from zero) in the set in O(logn) time
// set_name.order_of_key(k) It returns to the number of items that are strictly smaller than our item k in O(logn) time.
/*string operations :
str.substr (x,y) : returns a substring str[x],str[x+1],...str[x+y-1]
str.substr (x) : returns a substring str[x],... end of string
str.find(qtr) : returns the first occurenece of qtr in str */
int fun(int st,int k,const v &p,const v &c)
{
	int n=p.size();
	vb vst(n,false);
	vst[st]=true;
	int u=st;
	v cycle;
	cycle.pb(u);
	while(!vst[p[u]])
	{
		vst[p[u]]=true;
		cycle.pb(p[u]);
		u=p[u];
	}
	int loops=k/cycle.size();
	k%=cycle.size();
	if(loops==0)
	{
		int mx1,sum1=0;
		for(int i=1;i<=k;i++)
		{
			sum1+=c[cycle[i]];
			if(i==1 || mx1 < sum1)
				mx1=sum1;
		}
		return mx1;
	}
	int sum=0;
	for(auto it:cycle)
		sum+=c[it];


	// int ans=sum*loops;
	int ans1=(loops-1)*sum;
	int mx1;
	int sum1=0;
	for(int i=1;i<cycle.size();i++)
	{
		sum1+=c[cycle[i]];
		if(i==1 || sum1 > mx1)
			mx1=sum1;
	}
	if(loops==1)
		ans1+=mx1;
	else
		ans1+=max(mx1,0ll);
	int ans3=mx1;
	int ans2=(loops)*sum;
	sum1=0;
	mx1=0;
	for(int i=1;i<=k;i++)
	{
		sum1+=c[cycle[i]];
		if(mx1 < sum1)
			mx1=sum1;
		// ans+=c[cycle[i]];
	}
	ans2+=mx1;
	int ans=max({ans1,ans2,ans3});
	// ans-=c[st];
	return ans;

}
int32_t main()
{
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    int n,k;cin>>n>>k;
    v p(n);in(p,n);
    v c(n);in(c,n);
    f(i,n)
    	p[i]--;
    int mx;
    f(i,n)
    {
    	int ans=fun(i,k,p,c);
    	// cout<<ans<<endl;
    	if(i==0 || ans > mx)
    		mx=ans;
    	// mx=masx(mx,ans);
    }
    cout<<mx<<endl;
    return 0;
}

Measured memory_bytes: 3844