#include <bits/stdc++.h>
using namespace std;

#define itloop(it,x) for(auto it=x.begin();it!=x.end();it++)
#define reloop(i,e,b) for(auto i=e;i>=b;i--)
#define loop(i,b,e) for(auto i=b;i<=e;i++)
#define ALL(x) x.begin(),x.end()
#define SZ(x) x.size()
#define PB push_back
#define MP make_pair
#define F first
#define S second
#define sf scanf
#define pf printf
typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef pair<int,int> PI;
typedef pair<LL,LL> PL;

const int N=1e5+1;
LL ans;
int n,c,k,cost;
string s;
vector<string> words,msg;
map<string,int> m;

int main()
{
   sf("%d %d %d",&n,&k,&c);
   loop(i,1,n) {
      cin >> s;
      words.PB(s);
   }
   loop(i,0,n-1) {
      scanf("%d",&cost);
      m[words[i]] = cost;
   }
   loop(i,0,k-1) {
      int sz,x,mn=1e9+1;
      vector<int> v(N,0);
      sf("%d",&sz);
      loop(j,0,sz-1) {
         sf("%d",&v[i]);
         mn = min(mn,m[words[v[i]-1]]);
      }
      loop(j,0,sz-1)
         m[words[v[i]-1]] = mn;
   }
   loop(i,1,c) {
      cin >> s;
      ans += m[s];
   }
   pf("%lld",ans);
}