#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
#include<algorithm>
#include<string>
#include<set>
#include<map>
#include<vector>
#include<math.h>
#include<tuple>
#include<string.h>
#include <numeric> 
#include<unordered_map>
using namespace std; 
#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define pp(...) "\033[94m [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\033[0m"
#define pp1(...) "\033[1;47;35m" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\033[0m"
#define dg(x) debug() << pp1(x)
#define dg1(x) debug() << "[line : " << __LINE__ <<"]"<< pp(x)
#define dg2(x,y) debug() << "[line : " << __LINE__ <<"]"<< pp(x) pp(y)
#define dg3(x,y,z) debug() << "[line : " << __LINE__ <<"]"<< pp(x) pp(y) pp(z)
#define dg4(w,x,y,z) debug() << "[line : " << __LINE__ <<"]"<< pp(w) pp(x) pp(y) pp(z)
#define int long long
#define all(x) x.begin() , x.end()
#define clr(x , y) memset(x , y , sizeof x);
#define sz(x) (int)x.size()
template<typename T> void db(T x ){ debug() <<">>> " <<  x; }
template<typename T> void db(T x , T y){ debug() <<">>> " <<  x <<" , "<< y; }
template<typename T> void db(T x , T y , T z){ debug() <<">>> "<< x <<" , "<< y <<" , "<< z; }
template<typename T> void db(T x , T y , T z , T a){ debug() <<">>> "<< x <<" , " << y <<" , "<< z <<" , "<< a; }
const int xx = 2e5;
const int Mod = 1e9 + 7;
const int inf = 1e18;
const int Maxn = 20010;

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n , k;
  cin >> n >> k;
  vector<int> p(n + 1), c(n + 1);
  for(int i = 1; i <= n; i++) {
    cin >> p[i];
  }
  for(int i = 1; i <= n; i++) {
    cin >> c[i];
  }
  vector<int> totsum(n + 1, 0) , psum(n + 1,0), len(n + 1,0);

  for(int i = 1; i <= n; i++) {
    int sum = 0;
    int cur = p[i];
    int tk = k;
    int l = 0;
    int pMx = -inf;

    while(tk--) {
      // cout << cur << "> ";
      sum += c[cur];
      pMx = max(pMx, sum);
      l++;
      if(cur == i) break;
      cur = p[cur];
    }
    // cout << '\n';
    totsum[i] = sum;
    psum[i] = pMx;
    len[i] = l;
  }
  int ans = -inf;
  for(int i = 1; i<= n; i++) {
    dg4(i , totsum[i] , psum[i] , len[i]);
    int cnt = k / len[i];
    int rem = k % len[i];
    int Mx = -inf, sum = 0;
    int cur = p[i];
    while(rem --) {
      sum += c[cur];
      Mx = max(Mx , sum);
      if(cur == i) break;
      cur = p[cur];
    }
    if(cnt == 0) {
      ans = max({ans , psum[i]});
    } else {
      int res1 = (cnt * totsum[i]) + Mx;
      int res2 = ((cnt - 1) * totsum[i]) + psum[i];
      ans = max({ans , res1, res2});
    }
    ans = max(ans , psum[i]);
  }
  cout << ans << '\n';
}

Measured memory_bytes: 3776