#include <bits/stdc++.h>

const long long INF = 1e18;

const int N = 5e3;

int n, s;
int w[N + 5];
int p[N + 5];
int a[N + 5];

std::vector<std::pair<int, int>> adj[N + 5];

long long dp[N + 5][N + 5];
long long dpp[N + 5][N + 5];

std::vector<int> c;

bool in[N + 5];

void dfs(int u, int fath) {
	if (u == s) {
		dp[u][0] = -INF;
	}
	for (int i = 1; i <= n; i++) {
		if (i & 1) dp[u][i] += w[u];
		dp[u][i] -= (long long)p[u] * (i - (int)(u == s));
	}
	for (auto e : adj[u]) {
		int v = e.first;
		if (v != fath && !in[v]) {
			dfs(v, u);
			for (int i = 1; i <= n; i++)
				dp[u][i] += dpp[v][i];
		}
	}
	for (int i = 1; i <= n; i++)
		dpp[u][i] = std::max(dpp[u][i - 1], dp[u][i]);
}

int main() {
	#ifdef LOCAL
		freopen("data.in", "r", stdin);
//		freopen("data.out", "w", stdout);
	#endif
	
	std::ios::sync_with_stdio(false);
	
	std::cin >> n >> s;
	for (int i = 1; i <= n; i++)
		std::cin >> w[i];
	for (int i = 1; i <= n; i++)
		std::cin >> p[i];
	for (int i = 1; i <= n; i++)
		std::cin >> a[i];
	
	for (int i = 1; i <= n; i++)
		adj[a[i]].emplace_back(i, p[i]);
	
	std::vector<int> vis(n + 1);
	int x = s, cnt = 0;
	while (!vis[x]) {
		vis[x] = ++cnt;
		x = a[x];
	}
	for (int i = 1; i <= n; i++) {
		if (vis[i] && vis[x] <= vis[i] && vis[i] <= cnt) {
			in[i] = true;
		}
	}
	
	if (!in[s]) {
		dfs(s, 0);
		long long ans = std::max({dp[s][1], dp[s][2]});
		std::cout << ans << "\n";
	} else {
		c.emplace_back(s);
		for (int i = 1; i <= n; i++)
			if (in[i] && i != s) c.emplace_back(i);
		
		for (int i : c) {
			dfs(i, 0);
		}
		
		if (c.size() == 2) {
			long long ans = std::max({dp[c[0]][1], dp[c[0]][1] + dp[c[1]][1]});
			std::cout << ans << "\n";
		} else {
			long long ans = w[s];
			for (int i = 1; i <= n; i++) {
				long long sum1 = dp[s][i];
				long long sum2 = -INF;
				long long sum3 = -INF;
				for (int j = 1; j < (int)c.size(); j++) {
					int u = c[j];
					long long x = sum1 + dp[u][i];
					long long y = std::max(sum1, sum2) + dp[u][i - 1];
					long long z = i == 1 ? -INF : std::max(sum2, sum3) + dp[u][i - 2];
					sum1 = x;
					sum2 = y;
					sum3 = z;
				}
				ans = std::max({ans, sum1, sum2, sum3});
			}
			std::cout << ans << "\n";
		}
	}
	
	return 0;
}