#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cctype>
#include <cassert>
#include <climits>
#include <string>
#include <bitset>
#include <cfloat>
#include <random>
#include <iomanip>
#include <unordered_set>
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int,int> > vpii;
typedef vector<pair<ll,ll> > vpll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vc> vvc;
typedef vector<vs> vvs;
typedef vector<vll> vvll;
typedef map<int,int> mii;
typedef set<int> si;
#define rep(i,n) for(ll i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define arep(i,v) for(auto i : v)
#define irep(it, stl) for(auto it = stl.begin(); it != stl.end(); it++)
#define drep(i,n) for(int i = (n) - 1; i >= 0; --i)
#define fin(ans) cout << (ans) << '\n'
#define STLL(s) strtoll(s.c_str(), NULL, 10)
#define mp(p,q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define fi first
#define se second
constexpr int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
constexpr int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;} return 0;}
template <class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;} return 0;}
template <class T> inline void dump(T &v){irep(i, v){cout<<(*i)<<((i==--v.end())?'\n':' ');}}
inline string getline(){string s; getline(cin,s); return s;}
inline void yn(const bool b){b?fin("yes"):fin("no");}
inline void Yn(const bool b){b?fin("Yes"):fin("No");}
inline void YN(const bool b){b?fin("YES"):fin("NO");}
struct io{io(){ios::sync_with_stdio(false);cin.tie(0);}};
const int INF = INT_MAX;
constexpr ll LLINF = 1LL<<60;
constexpr ll MOD = 1000000007;
constexpr ld EPS = 1e-11;



int main() {
    
    ll n,K;
    cin>>n>>K;
    // if(n<k)k=n;
    vll p(n);
    vll c(n);
    rep(i,n){cin>>p[i];p[i]--;}
    rep(i,n)cin>>c[i];
    ll ans=-LLINF;

    rep(i,n){
        ll k=K;
        ll sum=0;
        ll pos=i;
        vll count(n,-LLINF);
        vll sz(n,0);
        ll j=-1;
        while(k>0){
            j++;
            ll next=p[pos];
            if(count[next]==-LLINF){
                sum+=c[next];
                count[next]=sum;
                sz[next]=j+1;
                // cout<<"A"<<i<<" "<<pos<<" "<<sum<<endl;
                chmax(ans,sum);
                pos=next;
                k--;
            }else {
                sum+=count[next];
                ll syu=sum-count[next];
                ll syunum=sz[pos]+1-sz[next];
                // cout<<k<<" "<<sum<<" "<<syu<<" "<<syunum<<endl;
                // dump(count);
                // dump(sz);
                if(k<syunum){
                    sum-=count[next];
                    count=vll(n,-LLINF);
                    sz=vll(n,0);
                    continue;
                }
                if(syu>0){
                    sum=count[next];
                    k=(K-sz[next])%syunum;
                    pos=next;
                    // cout<<sum<<" "<<k<<" "<<syunum<<" "<<sz[next]<<endl;
                    sum+=(K-sz[next])/syunum*syu;
                    // cout<<sum<<endl;
                    chmax(ans,sum);
                    count=vll(n,-LLINF);
                    sz=vll(n,0);
                }
                else break;
            }
        }
        // fin(ans);
        // fin("======================");
    }
    fin(ans);
}


Measured memory_bytes: 3772