#define LOCAL
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<(n); ++i)
#define rrep(i, n) for(int i=(n-1); i>=0; --i)
#define rep2(i, s, n) for(int i=s; i<(n); ++i)
#define ALL(v) (v).begin(), (v).end()
#define memr(dp, val) memset(dp, val, sizeof(dp))
using namespace std;
typedef long long ll;
static const int INTINF = (INT_MAX >> 1); // 10^9 + 10^7
static const ll LLINF = (LLONG_MAX >> 1);
static const int MAX = 100001;
static const ll MOD = 1000000007;
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 T int_ceil(T a, T b) { T res = a / b; if(a % b != 0) res++; return res; }
template<typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T> >;
string to_string(string s) { return '"' + s + '"'; }
string to_string(bool b) { return b ? "true" : "false"; }
template <size_t N> string to_string(bitset<N> bs) {
  string res;
  for (size_t i = 0; i < N; ++i) res += '0' + bs[i];
  return res;
}
string to_string(vector<bool> v) {
  string res = "{";
  for (bool e : v) res += to_string(e) + ", ";
  return res += "}";
}
template <class T, class U> string to_string(pair<T, U> p);
template <class C> string to_string(C c) {
  string res = "{";
  for (auto e : c) res += to_string(e) + ", ";
  return res += "}";
}
template <class T, class U> string to_string(pair<T, U> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
void debug() { cerr << '\n'; }
template <class Head, class... Tail> void debug(Head head, Tail... tail) {
  cerr << '\t' << to_string(head), debug(tail...);
}
#ifdef LOCAL
#define print(...) cerr << "[" << #__VA_ARGS__ << "]:", debug(__VA_ARGS__)
#else
#define print(...)
#endif

ll dp[5020];

class UnionFind{
    public:
        vector<ll> par; // 親
        vector<ll> rank; // 木の深さ
        ll numComponent; // 木の数
        void init(ll n){
            par.resize(n);
            rank.assign(n, 1LL);
            for(ll i=0; i<n; ++i) par[i] = i;
            numComponent = n;
        }

        ll findRoot(ll x){
            if(par[x] == x) return x;
            else return par[x] = findRoot(par[x]);
        }

        void unite(ll x, ll y){
            x = findRoot(x);
            y = findRoot(y);
            if(x == y) return;
            if(rank[x] < rank[y]) swap(x, y);
            rank[x] += rank[y];
            par[y] = x;
            numComponent--;
            return;
        }

        bool same(ll x, ll y){
            return findRoot(x) == findRoot(y);
        }

        ll size(ll x){
            return rank[findRoot(x)];
        }
};

int main(int argc, const char * argv[]) {
	std::cout << std::fixed << std::setprecision(15);

	memr(dp, 0);
	ll n, k; cin >> n >> k;
	vector<ll> p(n), c(n), v;
	rep(i, n){
		cin >> p[i];
		p[i]--;
	}
	rep(i, n){
		cin >> c[i];
	}

	UnionFind uf;
	uf.init(5050);
	rep(i, n){
		if(!uf.same(i, p[i]))
			uf.unite(i, p[i]);
		// if(v.size() == n + 1) break;
	}
	// print(v);
	rep(i, n){
		dp[uf.findRoot(i)] += c[i];
	}
	ll ans = -LLINF;
	rep(i, n){
		ll num = k;
		ll res = 0;
		int idx = i;
		if(uf.size(i) * 2 <= k && 0 < dp[uf.findRoot(i)]){
			// print(i);
			res += (k / uf.size(i) - 1) * dp[uf.findRoot(i)];
			num -=(k / uf.size(i) - 1) * uf.size(i);
			chmax(ans, res);
		}
		else{
			num = min(k, uf.size(i) * 2);
		}
		while(0 < num){
			res += c[p[idx]];
			chmax(ans, res);
			idx = p[idx];
			num--;
		}
	}

	cout << ans << endl;

	return 0;
}


Measured memory_bytes: 3784