#include<bits/stdc++.h>
using namespace std;
const int N=5005;
typedef long long ll;
vector<int>e[N];
int n,s,o,a[N],w[N],p[N],rg[N],cr,c[N],pr[N];
ll f[N][N],ans,s1,s2;
bool vis[N];
void dfs(int x){
	for(int i=1;i<=n;++i)f[x][i]=-1ll*p[x]*i+(i&1)*w[x];
	for(auto v:e[x])if(!vis[v]){
		dfs(v);
		ll mx=0;
		for(int j=1;j<=n;++j){
			mx=max(mx,f[v][j]);
			f[x][j]+=mx;
		}
	}
}
int main(){
	scanf("%d%d",&n,&s);
	for(int i=1;i<=n;++i)scanf("%d",&w[i]);
	for(int i=1;i<=n;++i)scanf("%d",&p[i]);
	for(int i=1;i<=n;++i){
		scanf("%d",&a[i]);
		e[a[i]].push_back(i);
	}
	for(o=s;!vis[o];o=a[o])vis[o]=true,rg[++cr]=o;
	if(o!=s){
		dfs(s);
		printf("%lld\n",max(f[s][1],f[s][2])+p[s]);
		return 0;
	}
	if(cr==2){
		dfs(s),dfs(rg[2]);
		printf("%lld\n",max(f[s][1]+max(f[rg[2]][0],f[rg[2]][1]),f[s][2])+p[s]);
		return 0;
	}
	for(int i=1;i<=cr;++i)dfs(rg[i]);
	for(int i=2;i<=cr;++i)pr[i]=i-1;
	pr[1]=cr,ans=f[s][2]+p[s];
	for(int i=1;;i=pr[i]){
		int x=rg[i],y=rg[pr[i]];
		if(c[y])s2-=max(0ll,f[y][c[y]+1]-f[y][c[y]]);
		s1-=f[x][c[x]];
		++c[x];
		if(c[x]>=n)break;
		s1+=f[x][c[x]];
		ans=max(ans,s1+s2+p[s]);
		s2+=max(0ll,f[x][c[x]+1]-f[x][c[x]]);
	}
	printf("%lld\n",ans);
	return 0;
}