/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

#include <iostream>
#include <fstream>

#include <iostream>
#include "bits/stdc++.h"

using namespace std;
typedef unsigned long long ll;
typedef int                     integer;
#define int                     long long
#define ii                      pair<int,int>
#define vii                     vector<pair<int,int>>
#define vi                      vector<int>
#define vvi                     vector<vector<int>>
#define f(a,b,c)                for(int a=b;a<c;a++)
#define s(x)                    in>>x
#define s2(x,y)                 in>>x>>y
#define s3(x,y,z)               in>>x>>y>>z
#define s4(x,y,z,w)             in>>x>>y>>z>>w
#define p(x)                    out<<x<<endl
#define p2(x,y)                 out<<x<<' '<<y<<endl
#define p3(x,y,z)               out<<x<<' '<<y<<' '<<z<<endl
#define p4(x,y,z,w)             out<<x<<' '<<y<<' '<<z<<' '<<w<<endl
#define pl(x)                   out<<x
#define pll(x)                  out<<x<<' '
#define range(v)                v.begin(),v.end()
#define rst(x)                  memset(x, -1, sizeof(x))
#define UNVISITED               -1
#define VISITED                 0
#define EXPLORED                2

#define EACH(x, a) for (auto& x: a)
template<class T> void read_v(T& x, std::istream& in) {
    in >> (x);
}
template<class A> void read_vec(vector<A>& x, std::istream& in) {
    EACH(a, x)
        read_v(a, in);
}

bool sortpairbysec(const pair<int,int> &a,const pair<int,int> &b){return (a.second < b.second);}
template <typename T>
T factmod(T a, T modulus){ int res = 1, i; for (i = 2; i <= a; i++){ res *= i; res%=modulus;} return res; }
template <typename T>
int powmod(T a,T b,int m){ int ans=1; while(b>0){if(b&1){ans*=a;ans%=m;}a*=a;a%=m;b>>=1;} return ans; }
template <typename T>
int power(T a, T b){ int ans=1; while(b>0){if(b&1){ans*=a;}a*=a;b>>=1;}return ans;}


void ssolve(std::istream& in, std::ostream& out){
    int n, k; s2(n, k);
    vi pe(n + 1, -1);
    f(i, 1, n + 1){
        s(pe[i]);
    }
    vi c(n + 1, LONG_LONG_MIN);
    f(i, 1, n + 1){
        s(c[i]);
    }
    int ans = *min_element(c.begin() + 1, c.end());
    f(i, 1, n + 1){
        int aux = 0;
        int curr = i;
        int cycle_sum = 0;
        int clen = 0;
        if(pe[curr]==curr){
            cycle_sum = c[curr];
            clen = 1;
        }else{
            while(curr != i || clen == 0){
                clen++;
                cycle_sum += c[curr];
                curr = pe[curr];
            }
        }

        int walk = k;
        int complete_walks = walk/clen;
        int non_complete_walks = walk%clen;

        if(complete_walks >= 1){
            if(cycle_sum>0){
                int copy_aux = aux;
                aux += (complete_walks * cycle_sum);
                ans = max(ans, aux);
                f(k2, 0, non_complete_walks){
                    curr = pe[curr];
                    aux += c[curr];
                    ans = max(ans, aux);
                }

                copy_aux += ((complete_walks - 1) * cycle_sum);
                ans = max(ans, copy_aux);
                f(k2, 0, clen){
                    curr = pe[curr];
                    copy_aux += c[curr];
                    ans = max(ans, copy_aux);
                }
            }else{
                f(k2, 0, clen){
                    curr = pe[curr];
                    aux += c[curr];
                    ans = max(ans, aux);
                }
            }
        }else{
            f(k2, 0, non_complete_walks){
                curr = pe[curr];
                aux += c[curr];
                ans = max(ans, aux);
            }
        }
    }
    p(ans);
    return;
}

class DMovingPiece {
public:
void solve(std::istream& in, std::ostream& out) {
    ios_base::sync_with_stdio(false);
    in.tie(nullptr);out.tie(nullptr);
    int t;
    int READ = 0;
    if(READ) s(t);
    else t = 1;
    while(t--){
        ssolve(in, out);
    }
}
};

integer main() {
    DMovingPiece solver;
    std::istream& in(std::cin);
     std::ostream& out(std::cout);
     solver.solve(in, out);
}

Measured memory_bytes: 3712