#include<bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// macros
#define int long long 
#define ll long long 
#define ld long double
#define TIME clock() * 1.0 / CLOCKS_PER_SEC
#define sz(x) ((int)((x).size()))

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(1, s));
}
 
string to_string(const char* s) {
  return to_string((string) s);
}
 
string to_string(bool b) {
  return (b ? "1" : "0");
}
 
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 debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

template <typename T1, typename T2>
inline auto mini(T1 a, T2 b) { return (a < b ? a : b); }
template<typename T, typename... Args>
inline auto mini(T a, Args... args) { return mini(a, mini(args...)); }
template <typename T1, typename T2>
inline auto maxi(T1 a, T2 b) { return (a > b ? a : b); }
template<typename T, typename... Args>
inline auto maxi(T a, Args... args) { return maxi(a, maxi(args...)); }
template<typename T>
T gcd(T a, T b) { if(a==0 or b==0) return a+b; return gcd(b, a%b) ; }
template<typename T>
T lcm(T a, T b) { if(a==0 or b==0) return 0; return a/gcd(a, b)*b; }

// random number generator
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); // use mt19937_64 for 64 bit

// constants
const long double eps = LDBL_EPSILON;
const int inf = 1e18;
const int modn = 1e9+7;
const int maxn = 2e5+3;

int solve(vector<int> a, int k) {
	int n = a.size();
	if(n == 1) {
		return max(a[0], k * a[0]);
	}
	vector<int> pref(n);
	pref[0] = a[0];
	for(int i = 1; i < n; i++) {
		pref[i] = a[i] + pref[i - 1];
	}
	vector<int> dp(n + 1, -inf);
	for(int i = 0; i < n; i++) {
		for(int j = i; j < n; j++) {
			int len = j - i + 1;
			int cur = pref[j] - (i >= 1 ? pref[i - 1] : 0);
			dp[len] = max(dp[len], cur);
			int sum1 = (i >= 1 ? pref[i - 1] : 0);
			int sum2 = pref[n - 1] - pref[j];
			int len2 = n - len;
			dp[len2] = max(dp[len2], sum1 + sum2);
		}
	}
	if(k >= n) {
		int ans = *max_element(dp.begin() + 1, dp.end());
		int sum = accumulate(a.begin(), a.end(), 0LL);
		if(sum < 0) {
			return ans;
		}
		int no = k / n;
		int ans2 = no * sum;
		for(int i = 1; i <= k % n; i++) {
			ans = max(ans, ans2 + dp[i]);
		}
		no--;
		ans2 = no * sum;
		for(int i = 1; i <= n; i++) {
			ans = max(ans, ans2 + dp[i]);
		}
		return ans;
	}
	else {
		int ans = -inf;
		for(int len = 1; len <= k; len++) {
			ans = max(ans, dp[len]);
		}
		return ans;
	}
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    // Your code here
    int n, k;
    cin >> n >> k;
    vector<int> p(n), c(n);
    for(int i = 0 ; i < n; i++) {
    	cin >> p[i];
    	p[i]--;
    }
    for(int i = 0 ; i< n; i++) {
    	cin >> c[i];
    }
    vector<bool> mark(n);
    vector<vector<int>> all_arr;
    for(int i = 0; i < n; i++) {
    	if(mark[i]) continue;
    	int cur = p[i];
    	vector<int> arr{c[i]};
    	mark[i] = 1;
    	while(cur != i) {
    		arr.push_back(c[cur]);
    		mark[cur] = 1;
    		cur = p[cur];
    	}
    	all_arr.push_back(arr);
    }
    // debug(all_arr);
    int ans = -inf;
    for(auto arr : all_arr) {
    	int cur = solve(arr, k);
    	// debug(cur);
    	ans = max(ans, cur);
    }
    cout << ans << "\n";
    return 0;
}

Measured memory_bytes: 3872