#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int N=5005;
int n,rt,to[N],q[N],hd=1,tl,deg[N];
ll p[N],w[N],dp[N][N],s0[N],s1[N];
bool vis[N];
vector<int>g[N];
void dfs(int u)
{
    for(int i=1;i<=n;++i)dp[u][i]=(i&1?w[u]:0)-i*p[u];
    for(int v:g[u])
    {
        dfs(v);
        ll mx=0;
        for(int i=1;i<=n;++i)mx=max(mx,dp[v][i]),dp[u][i]+=mx;
    }
}
int main()
{
    scanf("%d%d",&n,&rt);
    for(int i=1;i<=n;++i)scanf("%lld",w+i);
    for(int i=1;i<=n;++i)scanf("%lld",p+i);
    for(int i=1;i<=n;++i)scanf("%d",to+i),g[to[i]].push_back(i),++deg[to[i]];
    for(int i=1;i<=n;++i)if(!g[i].size())q[++tl]=i;
    while(hd<=tl)
    {
        int u=q[hd++];
        if(!--deg[to[u]])vis[to[u]]=1,q[++tl]=to[u];
    }
    if(vis[rt])
    {
        dfs(rt);
        printf("%lld\n",max(dp[rt][1],dp[rt][2])+p[rt]);
    }
    else
    {
        
        vector<int>cir;
        for(int u=rt;!vis[u];u=to[u])cir.push_back(u),vis[u]=1;
        for(int i=0;i<cir.size();++i)
            g[cir[i]].erase(find(g[cir[i]].begin(),g[cir[i]].end(),i==0?cir.back():cir[i-1]));
        reverse(cir.begin()+1,cir.end());
        for(int i:cir)dfs(i);
        if(cir.size()==2)
            printf("%lld\n",max({dp[rt][1],dp[rt][2],dp[rt][1]+dp[cir[1]][1]})+p[rt]);
        else
        {
            ll ans=-1e18;
            for(int x=1;x<=n;++x)
            {
                ll s0=dp[rt][x],s1=dp[rt][x],s2=dp[rt][x];
                for(int i=1;i<cir.size();++i)
                {
                    if(x>1)s0+=dp[cir[i]][x-2];
                    s1+=dp[cir[i]][x-1],s2+=dp[cir[i]][x];
                    s1=max(s1,s2),s0=max(s0,s1);
                }
                ans=max(ans,x==1?s1:s0);
            }
            printf("%lld\n",ans+p[rt]);
        }
    }
}