#include <bits/stdc++.h>
	
using namespace std;
 
#define int long long
 
#define PB	push_back
#define ALL(x)	(x).begin(), (x).end()
#define ALLR(x)	(x).rbegin(), (x).rend()
#define MP	make_pair
 
template <typename A, typename B>
string to_string(pair<A, B> p);
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
 
string to_string(const string& s) {
  return '"' + s + '"';
}
 
string to_string(const char* s) {
  return to_string((string) s);
}
 
string to_string(bool b) {
  return (b ? "true" : "false");
}
 
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
 
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
 
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
 
void debug_out() { cerr << endl; }
 
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
//~ #define LOCAL
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
 
#define FAST_IO ios::sync_with_stdio(false); cin.tie(0)
 
typedef pair<int, int> ii;
typedef pair<pair<int, int>, int> iii;
typedef vector<int> vi;
typedef vector<iii> viii;
typedef vector<vi> vvi;
typedef vector<ii> vii;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef unsigned long long ull;
 
const int INF = LONG_LONG_MAX;
const int NINF = LONG_LONG_MIN/2;
const double PI = 3.141592653589793238;

//MODULAR ARITHMATIC
const int mmod = 1000000000 + 7;

int add(int a, int b, int m=mmod) {
	return (a%m + b%m)%m;
}

int sub(int a, int b, int m=mmod) {
    return (a%m - b%m + m)%m;
}

int mul(int a, int b, int m=mmod) {
	return ((a%m) * (b%m) % m);
}

int pwr(int a, int b, int m=mmod) {
    a %= m;
    int r = 1;
    while (b) {
		if (b&1) r = r*a%m;
		b >>= 1;
		a = a*a%m;
    }
    return r;
}

int inv(int a, int m=mmod) {
	return pwr(a, m-2, m);
}

struct Solve {
	Solve() {
		int n, k;
		cin >> n >> k;
		
		vi p(n), c(n);
		for (int i = 0; i < n; i++) cin >> p[i];
		for (int j = 0; j < n; j++) cin >> c[j];
		
		for (int i = 0; i < n; i++) p[i] -= 1;
		
		vb visited(n);
		vvi group;
		for (int i = 0; i < n; i++) {
			vi grp;
			int it = i;
			while (!visited[it]) {
				grp.push_back(c[it]);
				visited[it] = true;
				it = p[it];
			}
			if (grp.size()) group.push_back(grp);
		}
		debug(group);
		vi nfull((int)(group.size()));
		
		for (int i = 0; i < (int)group.size(); i++) {
			nfull[i] = k/(int)group[i].size();
		}
		debug(nfull);
		int fans = -INF;
		for (int i = 0; i < (int)group.size(); i++) {
			vi dup(group[i]);
			for (int j = 0; j < (int)group[i].size(); j++) {
				dup.PB(group[i][j]);
			}
			for (int j = 0; j < (int)group[i].size(); j++) {
				dup.PB(group[i][j]);
			}
			debug(dup);
			vi prefix((int)dup.size()+1);
			prefix[0] = 0;
			for (int j = 0; j < (int)dup.size(); j++) {
				prefix[j+1] = prefix[j] + dup[j];
			}
			debug(prefix);
			int ans = -INF;
			for (int l = 0; l < (int)group[i].size(); l++) {
				for (int r = l+1; r < (int)prefix.size() && (r-l) <= k; r++) {
					ans = max(ans, prefix[r] - prefix[l]);
					debug(l, r, ans);
				}
			}
			
			fans = max(fans, ans);
			
			int sum = prefix[(int)group[i].size()];
			if (sum <= 0) continue;
			
			sum = sum * (nfull[i]-1);
			debug(sum);
			int extra = k - (nfull[i]-1)*group[i].size();
			debug(extra);
			ans = -INF;
			for (int l = 0; l < (int)group[i].size(); l++) {
				for (int r = l+1; r < (int)prefix.size() && (r-l) <= extra; r++) {
					ans = max(ans, prefix[r]-prefix[l]);
					debug(ans+sum);
				}
			}
			fans = max(fans, sum+ans);
		}
		cout << fans << endl;
	}
};

int32_t main() {
	FAST_IO;
	
	bool multi = false;
	int T=1;
	if (multi)
		cin >> T;
	
	while (T-->0) {
		Solve me;
	}
}
// g++ -Wall -Wextra -pedantic -std=c++17 -O2 -Wshadow -Wformat=2 -Wfloat-equal -Wconversion -Wlogical-op -Wshift-overflow=2 -Wduplicated-cond -Wcast-qual -Wcast-align -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC -D_FORTIFY_SOURCE=2 -fsanitize=address -fsanitize=undefined -fno-sanitize-recover -fstack-protector


Measured memory_bytes: 3836