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

#define loop(i,b,e) for(auto i=b;i<=e;i++)
#define PB push_back
#define F first
#define S second
#define sf scanf
#define pf printf
typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VLL;

const int N=1e5+1;
LL ans,cost;
int n,c,k,sz;
string s,tmp;
vector<string> words,msg;
map<string,LL> 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) {
      LL mn = 1e12;
      sf("%d",&sz);
      int v[sz];
      loop(j,0,sz-1) {
         sf("%d",&v[j]);
         tmp = words[v[j]-1];
         mn = min(mn,m[tmp]);
      }
      loop(j,0,sz-1) {
         tmp = words[v[j]-1];
         m[tmp] = mn;
      }
   }
   loop(i,1,c) {
      cin >> s;
      ans += m[s];
   }
   pf("%lld",ans);
}