#include<iostream>

#include<cstring>

#include<algorithm>

#include<cstdio>

#include<vector>

#include<queue>

#define pb push_back

using namespace std;

const int M=5e5+;

int sum[M],book[M],jiu[M],head[M],dfn[M],low[M],vis[M],sta[M],cmp[M],dis[M],val[M],newval[M],tot,top,cnt,num;

vector<int>g[M];

struct node{

    int v,w,nextt;

}e[M];

void tarjan(int u,int f){

    dfn[u]=low[u]=++cnt;

    sta[++top]=u;

    vis[u]=;

    for(int i=;i<g[u].size();i++){

        int v=g[u][i];

        if(v==f)

            continue;

        if(!dfn[v]){

            tarjan(v,u);

            low[u]=min(low[u],low[v]);

        }

        else if(vis[v])

            low[u]=min(low[u],dfn[v]);

    }

    if(low[u]==dfn[u]){

        cmp[u]=++tot;

        int countt=val[u];

        vis[u]=;

        int len=top;

        while(sta[top]!=u){

            countt+=val[sta[top]];

            cmp[sta[top]]=tot;

            vis[sta[top--]]=;

        }

        top--;

        sum[tot]=len-top;

        newval[tot]=countt;

    }

}

void addedge(int u,int v,int w){

    e[num].v=v;

    e[num].w=w;

    e[num].nextt=head[u];

    head[u]=num++;

}

int spfa(int s,int t){

    for(int i=s;i<=t;i++)

        dis[i]=,vis[i]=;

    queue<int>que;

    que.push(s);

    while(!que.empty()){

        int u=que.front();

        que.pop();

        vis[u]=;

        for(int i=head[u];~i;i=e[i].nextt){

            int v=e[i].v;

            if(dis[v]<dis[u]+e[i].w){

                dis[v]=dis[u]+e[i].w;

                if(!vis[v])

                    vis[v]=,que.push(v);

            }

        }

    }

    return dis[t];

}

int main(){

    int n,m;

    scanf("%d%d",&n,&m);

    for(int i=;i<=n;i++)

        head[i]=-;

    for(int i=,u,v;i<=m;i++){

        scanf("%d%d",&u,&v);

        g[u].pb(v);

    }

    for(int i=;i<=n;i++)

        scanf("%d",&val[i]);

    int s,p;

    scanf("%d%d",&s,&p);

    for(int i=;i<=p;i++)

        scanf("%d",&jiu[i]);

    for(int i=;i<=n;i++)

        if(!dfn[i])

            tarjan(i,-);

    s=cmp[s];

    int t=tot+;

    for(int i=;i<=n;i++)

        for(int j=,v;j<g[i].size();j++){

            v=g[i][j];

            if(cmp[i]!=cmp[v]){

    //m            cout<<cmp[i]<<"!!!!!"<<cmp[v]<<"!!!!"<<newval[cmp[i]]<<endl;

                addedge(cmp[i],cmp[v],newval[cmp[i]]);

            }

        }

    for(int i=;i<=p;i++){

        if(book[cmp[jiu[i]]]==)

            continue;

        book[cmp[jiu[i]]]=;

        int w=newval[cmp[jiu[i]]];

    //    if(sum[cmp[jiu[i]]]>1)

    //        w=0;

    //        cout<<cmp[jiu[i]]<<"!!!!!"<<t<<"!!!!"<<w<<endl;

        addedge(cmp[jiu[i]],t,w);

    }

    printf("%d\n",spfa(s,t));

}