#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<ctime>
#define ll long long
#define N 600

ll n,m,k,to[N],f[N][N],p[N],can[N];

inline void floyd(){
	for(int i = 1;i <= n;++i)
	f[i][i] = 0;
	for(int k = 1;k <= n;++k)
	for(int i = 1;i <= n;++i)
	for(int j = 1;j <= n;++j)
	f[i][j] = std::min(f[i][j],f[i][k] + f[k][j]);
}

inline ll find(){
	ll ans = 0;
	for(int i = 1;i <= n;++i){
		ll tans = 0x7f7f7f7f;
		if(p[i])
		continue;
		for(int j = 1;j <= n;++j)
		if(p[j])
		tans = std::min(tans,f[i][j]);
//		std::cout<<i<<" "<<tans<<std::endl;
		ans = std::max(ans,tans);
	}
	return ans;
}

ll fans = 0x7f7f7f7f;

inline void SA(){
	double T = 5000;
	double eps = 1e-10;
	while(T >= eps){
		ll x,y;
		x = rand() % can[0] + 1;y = rand() % can[0] + 1;
		ll z = -find();
		std::swap(p[can[x]],p[can[y]]);
		ll w = find();
		z += w;
		if(z < 0)
		fans = std::min(fans,w);
		if(z >= 0 && exp(-z / T) * RAND_MAX <= rand())
		std::swap(p[can[x]],p[can[y]]);
		T *= 0.993;
	}
}

int main(){
	srand(3491062232);
	std::memset(f,0x3f,sizeof(f));
	scanf("%lld%lld%lld",&n,&m,&k);
	for(int i = 1;i <= n;++i)
	scanf("%lld",&to[i]),to[i] ++ ;
	for(int i = 1;i <= n;++i){
		ll x;
		scanf("%lld",&x);
		f[to[i]][i] = f[i][to[i]] = std::min(f[i][to[i]],x);
	}
	floyd();
	for(int i = 1;i <= m;++i){
		ll x;
		scanf("%lld",&x);
		p[x] = 1;
	}
	for(int i = 1;i <= n;++i){
		if(!p[i])
		can[++can[0]] = i;
	}
	ll ki = k;
	for(int i = 1;i <= n,ki;++i){
		if(!p[i])
		p[i] = 1,ki -- ;
	}
	fans = find();
	if(m + k == n)
	std::cout<<fans<<std::endl;
	else{
	while(((double)(clock())/CLOCKS_PER_SEC)<0.6)
	SA();
	std::cout<<fans<<std::endl;
	}
}