#include <bits/stdc++.h>
#define ll long long
#define endl "\n"
#define IOS ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
const ll MOD = 1e9 + 7;
const double EPS = 1e-7;
const int MAX = (int)1e5 + 10;
const double PI = acos(-1);
vector<int> adj[MAX];
vector<int> par[MAX];
vector<pair<int, int> > shits[MAX];
int frq[MAX] ;
bool removed[MAX];
int sqrt_n = 400;
void build(queue<int> q, vector<int> ind){
while(!q.empty()){
int curNode = q.front();
q.pop();
for(auto node : adj[curNode]){
ind[node]--;
if(ind[node] == 0) q.push(node);
}
vector<pair<int,int> > &res = shits[curNode];
res.push_back({0, curNode});
for(auto node : par[curNode]){
for(auto x : shits[node]){
frq[x.second] = max(frq[x.second], x.first + 1);
}
}
for(auto node : par[curNode]){
for(auto x : shits[node]){
if(frq[x.second] > 0){
res.push_back({frq[x.second], x.second});
frq[x.second] = 0 ;
}
}
}
sort(res.rbegin(), res.rend()) ;
while((int)res.size() > sqrt_n){
res.pop_back();
}
// cout << curNode << endl;
// for(auto x : res) cout << x.first << " " << x.second << endl ;
}
}
int bfs(queue<int> q, vector<int> ind, int n, int nodeParty)
{
vector<int> dis(n+1,0);
while (!q.empty())
{
int curNode = q.front();
q.pop();
for(auto node : adj[curNode]){
ind[node]-- ;
if(ind[node] == 0) q.push(node);
if(dis[curNode] == 0 && removed[curNode] == true) continue ;
dis[node] = max(dis[node], dis[curNode] + 1);
}
}
return dis[nodeParty];
}
void solve()
{
int n, m, q;
cin >> n >> m >> q;
vector<int> ind(n + 1, 0);
for (int i = 0; i < m; i++)
{
int u, v;
cin >> u >> v;
adj[u].push_back(v);
par[v].push_back(u);
ind[v]++;
}
queue<int> roots;
for (int i = 1; i <= n; i++)
{
if (ind[i] == 0) roots.push(i) ;
}
build(roots, ind);
while (q--)
{
int nodeParty, totalRemoved;
vector<int> rmv;
cin >> nodeParty >> totalRemoved;
for (int i = 1; i <= totalRemoved; i++)
{
int node;
cin >> node;
rmv.push_back(node);
}
for(auto node : rmv) removed[node] = true ;
int sz = (int)rmv.size();
int ans = -1;
if (sz > sqrt_n)
{ // FIRST TYPE OF QUESRIES
ans = bfs(roots, ind, n, nodeParty);
}
else
{
for(auto node : shits[nodeParty]){
if(removed[node.second] == false){
ans = max(ans,node.first);
}
}
}
if(ans == 0 && removed[nodeParty] == true) ans = -1;
cout << ans << endl ;
for(auto node : rmv) removed[node] = false ;
}
}
int main()
{
IOS;
solve();
return 0;
}
