/*
	Nishant Singh
	nishant.ns19@gmail.com
*/
#include <bits/stdc++.h>
#include <functional> 
#include <iostream> 
// ******** Big Integer ********
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;
// #define ll1024  int1024_t
// ******** Big Integer ********
// ******** Using PBDS ********
// #include <ext/pb_ds/assoc_container.hpp> // Common file 
// #include <ext/pb_ds/tree_policy.hpp> 
// using namespace __gnu_pbds; 
// #define ook order_of_key    //count of strictly smaller elements
// #define fbo find_by_order   //find element at an index 
// ******** Using PBDS ********
using namespace std;
#define ll long long
#define ld long double
#define pll pair<long long,long long>
#define pii pair<int,int>
#define vll vector<ll>
#define vec vector
#define setcount(x) __builtin_popcountll(x)
#define f first
#define s second
#define mp make_pair
#define REP(i,n) for(ll i=0;i<(n);i++)
#define FOR(i,a,b) for(ll i=(a);i<=(b);i++)
#define REV(i,a,b) for(ll i=(a);i>=(b);i--)
#define pb push_back
#define in insert
#define init(x,a) memset(x,a,sizeof(x))
#define all(c) c.begin(),c.end()
#define pq priority_queue
#define ffl fflush(stdout)
#define mset multiset
#define out(x) cout<<#x<<" = "<<" "<<x<<"\n";
#define ub upper_bound
#define lb lower_bound 
#define ln "\n"
#define Y "YES"
#define N "NO"
ll const mod=1e9 + 7;
ll const inf=2e15;
// ******** Using PBDS ********
// typedef tree<long long, null_type, less<long long>, rb_tree_tag, 
//              tree_order_statistics_node_update> 
//                 os; 
// ******** Using PBDS ********
inline ll add(ll a,ll b) 
{ 
	return (a%mod + b%mod + mod)%mod; 
}
inline ll mul(ll a,ll b) 
{ 
	return (a%mod * b%mod + mod)%mod; 
}
inline ll sub(ll a,ll b) 
{ 
	return (a%mod - b%mod + mod)%mod; 
}
ll gcd(ll a,ll b)
{
	if (b == 0) 
		return a; 
	return gcd(b, a % b);  
}
ll modexp(ll x, ll n){
	if(n==0){
		return 1;
	}
	else if(n&1){
		return (modexp((x*x)%mod, n/2)%mod * x%mod)%mod;
	}
	else{
		return (modexp((x*x)%mod, n/2)%mod);
	}
}
ll modinv(ll n)
{
	return modexp(n,mod-2);
}
// ******** GLOBAL VARIABLES ********
ll n,k;
ll p[50001],c[50001];
// ******** GLOBAL VARIABLES ********
void dfs(ll i,bool vis[],vll &v)
{
	if(vis[i])
		return;
	vis[i]=true;
	v.pb(c[p[i]]);
	dfs(p[i],vis,v);
}
void solve(){
	cin>>n>>k;
	REP(i,n)
	{
		cin>>p[i];
		p[i]--;
	}
	REP(i,n)
	{
		cin>>c[i];
	}
	ll ans=-1LL*inf;
	bool vis[n];
	init(vis,false);
	REP(i,n)
	{
		if(!vis[i])
		{
			vll temp;
			dfs(i,vis,temp);
			ll pre[2LL*temp.size()];
			REP(j,2LL*temp.size())
			{
				pre[j]=temp[j%temp.size()];
				if(j>0)
					pre[j]+=pre[j-1];
			}
			if(k<=temp.size())
			{
				for(ll sublength=1;sublength<=k;sublength++)
				{
					REP(j,temp.size())
					{
						if(j==0)
							ans=max(ans,pre[j+sublength-1]);
						else
							ans=max(ans,pre[j+sublength-1]-pre[j-1]);
					}
				}
			}
			else
			{
				if(pre[temp.size()-1]<=0)
				{
					for(ll sublength=1;sublength<=temp.size();sublength++)
					{
						REP(j,temp.size())
						{
							if(j==0)
								ans=max(ans,pre[j+sublength-1]);
							else
								ans=max(ans,pre[j+sublength-1]-pre[j-1]);
						}
					}
				}
				else
				{
					ll x=k/temp.size();
					ll curr=x*pre[temp.size()-1];
					ll left=k%temp.size();
					ans=max(ans,curr);
					for(ll sublength=1;sublength<=left;sublength++)
					{
						REP(j,temp.size())
						{
							if(j==0)
								ans=max(ans,pre[j+sublength-1]+curr);
							else
								ans=max(ans,pre[j+sublength-1]-pre[j-1]+curr);
						}
					}
					if(x>1)
					{
						curr=(x-1)*pre[temp.size()-1];
						for(ll sublength=1;sublength<=temp.size();sublength++)
						{
							REP(j,temp.size())
							{
								if(j==0)
									ans=max(ans,pre[j+sublength-1]+curr);
								else
									ans=max(ans,pre[j+sublength-1]-pre[j-1]+curr);
							}
						}

					}
				}
			}
		}
	}
	cout<<ans<<ln;
}  
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	ll T=1;
	// cin>>T; 	
	for(int t=1;t<=T;t++)
	{
		// cout<<"Case #"<<t<<": ";
		solve();
	}
	return 0;
}

Measured memory_bytes: 3912