#include<bits/stdc++.h>
//copy allowed;
#define ee <<endl;
#define vv ll l; cin>>l; vector<ll> a(l); for(ll i=0;i<l;i++)cin>>a[i]
#define tt ll t; cin>>t; while(t--)
#define pb push_back
#define fi first
#define prefs vector<ll> pref({0}); for(ll i:a)pref.pb(pref.back()+i)
#define se second
#define all(a) a.begin(),a.end()
#define ll long long
using namespace std;
int dist[100007];
int D=597;
int vis[100007];
vector<pair<int,int>> topk[100007];
const int inf = (1<<30);
queue<pair<int, int>> q_bfs;
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,m,q;
cin>>n>>m>>q;
vector<int> par[n+1];
for(int i=0;i<m;i++){
int x,y;
cin>>x>>y;
par[y].pb(x);
}
for(auto &i:topk)i.reserve(D+10);
vector<pair<int,int>> un;
for(int i=1;i<=n;i++){
topk[i] .pb( {0,i});
for(int parent:par[i]){
un = {};
un.reserve(D+1);
int jj=0;
for(int ii=0;ii<topk[i].size();ii++){
while(jj<topk[parent].size()&&topk[parent][jj].fi+1>=topk[i][ii].fi&&un.size()<D){
if(!vis[topk[parent][jj].se]){
vis[topk[parent][jj].se]=1;
un.pb({topk[parent][jj].fi+1,topk[parent][jj].se});
}
jj++;}
if(un.size()>=D)break;
if(!vis[topk[i][ii].se]){un.pb(topk[i][ii]); vis[topk[i][ii].se] = 1;}
}
if(un.size()<D&&jj<topk[parent].size()){
while(un.size()<D&&jj<topk[parent].size()){
un.pb({topk[parent][jj].fi+1,topk[parent][jj].se});
jj++;
}
}
for(auto& p : un) {
vis[p.se] = 0;
}
topk[i] = un;
}
}
while(q--){
int k;
cin>>k;
vv;
for(int i:a)vis[i]++;
if(l<D){
bool g=0;
for(pair<int,int> i:topk[k]){
if(!vis[i.se]){
cout<<i.fi ee; g=1; break;
}
}
if(!g)cout<<-1 ee;
}
else{
q_bfs.push({k, 0});
for(int j=1; j<=n; j++) dist[j] = -1;
dist[k] = 0;
while (!q_bfs.empty()) {
auto [cur, d] = q_bfs.front();
q_bfs.pop();
if (d < dist[cur]) continue;
for (int parent : par[cur]) {
if (dist[parent] < dist[cur] + 1) {
dist[parent] = dist[cur] + 1;
q_bfs.push({parent, dist[parent]});
}
}
}
int mx=-1;
for(int i=1;i<=n;i++){
if(!vis[i])
mx = max(mx,dist[i]);
}
cout << mx ee;
}
for(int i:a)vis[i]=0;
}
}
