//----AUTHOR:kkdrummer----/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
//#include <boost/multiprecision/cpp_int.hpp> 
//using namespace boost::multiprecision; 
using namespace __gnu_pbds;
using namespace std;
typedef    long long                	 ll;
typedef    long double              	 ld;
typedef    unordered_set<ll>         	 usll;
typedef    unordered_multiset<ll>    	 umsll;
typedef    multiset<ll>              	 msll;
typedef    set<ll>                  	 sll;
typedef    vector<ll>               	 vll;
typedef    pair<ll,ll>              	 pll;
typedef    vector<pll>              	 vpll;
typedef    priority_queue<ll>       	 pqll;
typedef    vector<int>              	 vi;
typedef    set<int>                 	 si;
typedef    multiset<int>            	 msi;
typedef    unordered_multiset<int>  	 umsi;
typedef    unordered_set<int>       	 usi;
typedef    pair<int,int>               	 pi;
typedef    vector<pi>                	 vpi;
typedef    priority_queue<int>       	 pqi;
typedef    tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>   ind_si;
typedef    tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>   ind_sll;
typedef    tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update>   ind_msi;
typedef    tree<ll,null_type,less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update>   ind_msll;
#define    in          		insert
#define    fi          		first
#define    se          		second
#define    pb   	    	push_back
#define    mp   	   		make_pair
#define    be   	   		begin
#define    en   	   		end
#define    itr  	   		iterator
#define    io  	       		ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define    mo   	   		1000000007
#define    inf  	   		8222372026854775807
#define    ninf   	   		-inf
#define    ima   	   		1147483647
#define    imi   	   		-ima
#define    oncnt       		__builtin_popcount
#define    zerobegin   		__builtin_clz
#define    zeroend    		__builtin_ctz
#define    parity      		__builtin_parity
#define    all(x)      		x.be(),x.en()
#define    eps         		1e-9
#define    coutd       		cout<<setprecision(12)<<fixed
#define    mems(dp,x)  		memset(dp,x,sizeof(dp))
#define    fbo         		find_by_order
#define    ook    	   		order_of_key
#define    upb    	   		upper_bound
#define    lowb  	   		lower_bound 
#define    lte(v,x)    		upb(all(v),x)-v.be()
#define    gte(v,x)    		v.end()-lowb(all(v),x)
#define    gt(v,x)     		v.en()-upb(all(v),x)
#define    lt(v,x)     		lowb(all(v),x)-v.be()
const      ld PI= 			3.1415926535897932384626433832792884197169399375105820974944;
inline ll modpow(ll x,ll n){if(n==0)return 1;if(x==0)return 0;if(n==1)return(x%mo);ll u=(modpow(x,n/2));u=(u*u)%mo;if(n%2!=0)u=(u*x%mo)%mo;return u;}
inline ll modinv(ll x){return modpow(x,mo-2);}
inline ll mmul(ll a,ll b){if(a>=mo)a=a%mo;if(b>=mo)b=b%mo;if(a*b>=mo)return(a*b)%mo;return(a*b);}
inline ll madd(ll a, ll b){if(a>=mo)a=a%mo;if(b>=mo)b=b%mo;if(a+b>=mo)return(a+b)%mo;return(a+b);}
inline ll msub(ll a, ll b){if(a>=mo)a=a%mo;if(b>=mo)b=b%mo;return(((a-b)%mo+mo)%mo);}
inline ll mdiv(ll a,ll bb){if(a>=mo)a=a%mo;ll b=modinv(bb);if(b>=mo)b=b%mo;if(a*b>=mo)return(a*b)%mo;return(a*b);}
inline ll gcd(ll a,ll b){return __gcd(a,b);}
inline ll lcm(ll a,ll b){return (a*b)/gcd(a,b);}
 
 



int main()
{                io 
int testcases=1;              //           cin>>testcases;
while(testcases--)
{

ll n,k;
cin>>n>>k;

int p[n+1];
for(int i=1;i<=n;i++)
cin>>p[i];

ll c[n+1];
for(int i=1;i<=n;i++)
cin>>c[i];

ll ma=ninf;

for(int i=1;i<=n;i++)
{
	int st=i;
	ll va=c[p[st]];
	//ma=max(ma,va);
	int id=p[st];
	vll vh;
	vh.pb(va);
	ll siz=1;
	while(id!=st)
	{
	
		va+=c[p[id]];
		vh.pb(va);
		id=p[id];
		siz++;
	}
	
	ll qu=k/siz;
	ll rem=k-siz*qu;
	//cout<<qu<<" "<<rem<<"\n";
	//cout<<va<<"\n";
	
	if(k>siz)
	{		ll pma=ninf;
	for(int j=0;j<siz;j++)
	pma=max(pma,vh[j]);
	ma=max(ma,pma);
		if(va>0)
		{
			ll rma=0;
			for(int j=0;j<rem;j++)
			{
				rma=max(rma,vh[j]);
			}
			//cout<<rma<<'\n';
			ma=max(ma,va*qu+rma);
			if(qu>=1)
			{
				ma=max(ma,va*(qu-1)+pma);
			}
		}
	}
	
	
	else
	{
		for(int j=0;j<k;j++)
		ma=max(ma,vh[j]);
	}
	

	
}


cout<<ma;












































































 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
}return 0;}

Measured memory_bytes: 3808