#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
int k;
vector<vector<int>> addn;
vector<vector<int>> remn;
vector< set<pii> > st;
vector< set<pii> > stt;
vector<int> dp;
void dfs(int x){
for(auto u : remn[x]){
for(auto p : st[u]){
pii tmp = p;
auto ss = stt[x].lower_bound({tmp.second,-1});
if(ss != stt[x].end() && ss->first == tmp.second){
pii dd = *ss;
if(dd.second < tmp.first+1){
auto it = st[x].find({dd.second,dd.first});
if(it != st[x].end()) st[x].erase(it);
stt[x].erase(ss);
st[x].insert({tmp.first+1,tmp.second});
stt[x].insert({tmp.second,tmp.first+1});
}
} else {
st[x].insert({tmp.first+1,tmp.second});
stt[x].insert({tmp.second,tmp.first+1});
}
}
st[x].insert({1,u});
stt[x].insert({u,1});
while((int)st[x].size() > k){
pii tmp = *st[x].begin();
st[x].erase(st[x].find(tmp));
auto it2 = stt[x].find({tmp.second,tmp.first});
if(it2 != stt[x].end()) stt[x].erase(it2);
}
}
st[x].insert({0,x});
stt[x].insert({x,0});
while((int)st[x].size() > k){
auto it = st[x].begin();
pii ss = *it;
st[x].erase(it);
auto it2 = stt[x].find({ss.second,ss.first});
if(it2 != stt[x].end()) stt[x].erase(it2);
}
}
void ddfs(int x){
for(auto v : addn[x]){
if(dp[v] == -1000000000) continue;
if(dp[x] < dp[v] + 1) dp[x] = dp[v] + 1;
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n,m,q;
if(!(cin >> n >> m >> q)) return 0;
k = (int)sqrt(n) + 1;
addn.assign(n+1, vector<int>());
remn.assign(n+1, vector<int>());
st.assign(n+1, set<pii>());
stt.assign(n+1, set<pii>());
dp.assign(n+1, 0);
for(int i=0;i<m;i++){
int u,v;
cin >> u >> v;
addn[u].push_back(v);
remn[v].push_back(u);
}
for(int i=1;i<=n;i++) dfs(i);
while(q--){
int T;
cin >> T;
int Y;
cin >> Y;
set<int> busy;
for(int i=0;i<Y;i++){
int c; cin >> c;
busy.insert(c);
}
if((int)busy.size() < k){
int ans = -1000000000;
for(auto p : st[T]){
if(busy.find(p.second) == busy.end()) ans = max(ans, p.first);
}
if(ans == -1000000000) cout << -1 << '\n';
else cout << ans << '\n';
} else {
for(int i=1;i<=n;i++) dp[i] = -1000000000;
dp[T] = 0;
for(int i=T;i>0;i--) ddfs(i);
int ans = -1000000000;
for(int i=1;i<=T;i++){
if(!busy.count(i)) ans = max(ans, dp[i]);
}
if(ans == -1000000000) cout << -1 << '\n';
else cout << ans << '\n';
}
}
return 0;
}
