#include <bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N,M,Q;
if(!(cin>>N>>M>>Q)) return 0;
int k = (int)sqrt(N) + 1;
vector<vector<int>> add(N+1), rem(N+1);
for(int i=0;i<M;i++){
int s,e; cin>>s>>e;
add[s].push_back(e);
rem[e].push_back(s);
}
vector<vector<pii>> st(N+1);
vector<int> seen(N+1, 0), best(N+1, 0);
for(int v=1; v<=N; ++v){
vector<int> list_srcs; list_srcs.reserve( max(1, (int)rem[v].size()*min(k,5)) );
for(int u : rem[v]){
auto &su = st[u];
for(auto &p : su){
int src = p.second;
int val = p.first + 1;
if(seen[src] != v){
seen[src] = v;
best[src] = val;
list_srcs.push_back(src);
} else if(best[src] < val){
best[src] = val;
}
}
if(seen[u] != v){
seen[u] = v;
best[u] = 1;
list_srcs.push_back(u);
} else if(best[u] < 1){
best[u] = 1;
}
}
if(seen[v] != v){
seen[v] = v;
best[v] = 0;
list_srcs.push_back(v);
} else if(best[v] < 0){
best[v] = 0;
}
vector<pii> items; items.reserve(list_srcs.size());
for(int src : list_srcs) items.emplace_back(best[src], src);
if((int)items.size() > k){
auto cmp = [](const pii &a, const pii &b){ return a.first > b.first; };
nth_element(items.begin(), items.begin()+k, items.end(), cmp);
items.resize(k);
sort(items.begin(), items.end(), cmp);
} else {
sort(items.begin(), items.end(), [](const pii &a, const pii &b){ return a.first > b.first; });
}
st[v].swap(items);
}
vector<int> dp(N+1, -1000000000);
while(Q--){
int T, Y;
cin >> T >> Y;
vector<int> busy(Y);
for(int i=0;i<Y;i++) cin>>busy[i];
if(Y < k){
unordered_set<int> busyset;
busyset.reserve(Y*2+1);
for(int b : busy) busyset.insert(b);
int ans = -1000000000;
for(auto &p : st[T]){
if(busyset.find(p.second) == busyset.end()){
ans = max(ans, p.first);
break;
}
}
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 x=T; x>=1; --x){
if(dp[x] == -1000000000) continue;
for(int u : rem[x]){ }
for(int v : add[x]){
if(dp[v] != -1000000000){
}
}
int bestx = dp[x];
for(int v: add[x]){
if(dp[v] != -1000000000) bestx = max(bestx, dp[v] + 1);
}
dp[x] = bestx;
}
vector<char> isbusy(T+1, 0);
for(int b: busy) if(b<=T) isbusy[b]=1;
int ans = -1000000000;
for(int i=1;i<=T;i++){
if(!isbusy[i]) ans = max(ans, dp[i]);
}
if(ans == -1000000000) cout << -1 << '\n';
else cout << ans << '\n';
}
}
return 0;
}
