#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define pii pair<int, int>
#define ld long double
#define all(a) (a).begin(), (a).end()

const int MAXN = 5050;

vector<int> G[MAXN];

int n;

int A[MAXN];
long long w[MAXN];
long long p[MAXN];

long long dp[MAXN][MAXN];
long long pref_mx[MAXN][MAXN];

void dfs(int v) {
    for (int k = 0; k <= n; ++k) {
        dp[v][k] = k % 2 ? w[v] : 0;
    }
    for (int u : G[v]) {
        dfs(u);
        for (int k = 0; k <= n; ++k)
            dp[v][k] += pref_mx[u][k];
    }
    pref_mx[v][0] = dp[v][0];
    for (int k = 1; k <= n; ++k)
        pref_mx[v][k] = max(pref_mx[v][k - 1], dp[v][k] - p[v] * 1ll * k);
}

long long pref_sum[MAXN][MAXN];

const long long INF = 1e18;

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int s;
    cin >> n >> s;
    --s;
    for (int i = 0; i < n; ++i)
        cin >> w[i];
    for (int i = 0; i < n; ++i)
        cin >> p[i];
    for (int i = 0; i < n; ++i) {
        cin >> A[i];
        --A[i];
    }
    vector<bool> used(n, false);
    vector<int> cycle;
    int cur = s;
    while (!used[cur]) {
        used[cur] = true;
        cycle.emplace_back(cur);
        cur = A[cur];
    }
    for (int i = 0; i < n; ++i) {
        if (!used[i])
            G[A[i]].emplace_back(i);
    }
    if (cur != s) {
        // no cycle, just s
        dfs(s);
        cout << max(dp[s][0], dp[s][1] - p[s]) << '\n';
    } else {
        // have a cycle
        reverse(cycle.begin() + 1, cycle.end());
        for (int j = 0; j < cycle.size(); ++j)
            dfs(cycle[j]);
        for (int k = 0; k <= n; ++k) {
            pref_sum[k][0] = 0;
            for (int j = 0; j < cycle.size(); ++j)
                pref_sum[k][j + 1] = pref_sum[k][j] + dp[cycle[j]][k] - p[cycle[j]] * k;
        }
        long long ans = -INF;
        for (int k = 1; k + 1 <= n; k += 2) {
            long long l_mx = pref_sum[k + 1][0] - pref_sum[k][0];
            for (int r = 1; r <= cycle.size(); ++r) {
                l_mx = max(l_mx, pref_sum[k + 1][r] - pref_sum[k][r]);
                long long cur_r = pref_sum[k][r] - pref_sum[k - 1][r];
                ans = max(ans, l_mx + cur_r + pref_sum[k - 1][cycle.size()]);
            }
        }
        cout << ans + p[s] << '\n';
    }
    return 0;
}