#include <bits/stdc++.h>
using namespace std;
#define X ios_base::sync_with_stdio(false); cin.tie(NULL);
#define FIXED_FLOAT(x) std::fixed <<std::setprecision(2)<<(x)
 
 
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
 
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
 
 
// long long p = 1e9+7;
 
typedef long long ll;
typedef pair<ll,ll> pl;
typedef vector<int> VI;
typedef vector<pair<ll,ll>> VP;
typedef vector<ll> VL;
typedef vector<VL> VVL;
typedef vector<bool> VB;
 
// typedef pair<ll, ll> PL;
typedef unordered_map<ll, ll> UMP;
#define FOR(i,b,init) for(i=init;i<b;i++)
#define pb push_back
#define fi first
#define se second
#define mp make_pair
 
// typedef  unordered_set<ll>;
 
 
// void printa(VI &x,ll n){
//     ll i;
//     FOR(i, n){
//         cout<<x[i]<<" ";
//     }
//     cout<<endl;
// }
 
 

/////GLOABLS VARS
ll MOD = 1e9+7;
ll gmx = 1e6+7; 

VL fact(gmx, 1);
//////FUNCTIONS
ll powp(ll val, ll deg)
{
    // debug(val, deg);
    if (!deg)
        return 1;
    if (deg & 1)
        return (powp(val, deg - 1) * val) % MOD;
    ll res = powp(val, deg >> 1);
    // debug(res);
    return (res * res) % MOD;
}




//It is not easy but it can be fun, if you think!!!

//
// ll mx = 2*1e5+7;
vector<vector<pl>> adj;


int main(){
      ios::sync_with_stdio(0);
      cin.tie(0);
    // #ifndef ONLINE_JUDGE
    //     freopen("input.txt", "r", stdin);
    //     freopen("output.txt", "w", stdout);
    //     #define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
    // #endif
    ll tc,i;
    ll n,k;
    cin>>n>>k;
    VL p(n), c(n);
    FOR(i,n,0){
        cin>>p[i];
        p[i]--;
    }
    FOR(i,n,0){
        cin>>c[i];
    }
    ll ind;
    ll fans=-1e18;
    FOR(ind,n,0){
        ll i = ind;

        ll kc = k;
        ll j=ind;
        ll scf=c[p[ind]];
        ll sc=0;
        VL cyc;
        ll cys = 0;
        VL vis2(n,0);
        j = i;
        while(vis2[j]==0){
            cyc.pb(c[p[j]]);
            vis2[j]=1;
            j = p[j];
            cys+=c[j];
        }
        ll clen = cyc.size();
        // ll sc_dup = -1e18;
        if(cys>0){
            if(kc%clen==0){
                sc+=((kc/clen)-1)*cys;
                // sc_dup = (kc/clen)*cys;
                scf = max(sc,scf);
                kc-=((kc/clen)-1)*clen;                
            }
            else{
                sc+=(kc/clen)*cys;
                // sc_dup = (kc/clen)*cys;
                scf = max(sc,scf);
                kc-=((kc/clen))*clen;
            }

        }
        // debug(scf,sc);
        // sc=0;
        i = ind;
        FOR(j,min(kc, clen),0){
            i = p[i];
            sc+=c[i];
            scf = max(sc, scf);
        }
        fans = max(fans, scf);
        // fans = max(fans, sc_dup);
        // debug(ind, scf);

    }
    cout<<fans;
}

Measured memory_bytes: 11348