#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5;
const int TRESH = 350;
vector<int> adj[MAXN];
vector<int> revAdj[MAXN];
vector<pair<int, int>> furthest[MAXN];
int nbSommets, nbAretes;
vector<int> naiveDp(int source) {
vector<int> dp(nbSommets, -1);
dp[source] = 0;
for (int iSommet = source - 1; iSommet >= 0; --iSommet)
for (auto iFils : adj[iSommet])
if (dp[iFils] >= 0)
dp[iSommet] = max(dp[iSommet], dp[iFils] + 1);
return dp;
}
void init() {
for (int iSommet = 0; iSommet < nbSommets; ++iSommet) {
priority_queue<tuple<int, int, int>> pq;
for (auto v : revAdj[iSommet]) {
assert(!furthest[v].empty());
auto [u, d] = furthest[v].back();
pq.emplace(d, v, (int)furthest[v].size() - 1);
}
for (int iter = 0; iter < TRESH and !pq.empty(); ++iter) {
auto [dis, from, id] = pq.top();
pq.pop();
furthest[iSommet].emplace_back(furthest[from][id].first,
furthest[from][id].second + 1);
if (id > 0)
pq.emplace(furthest[from][id - 1].second, from, id - 1);
}
if ((int)furthest[iSommet].size() < TRESH)
furthest[iSommet].emplace_back(iSommet, 0);
reverse(furthest[iSommet].begin(), furthest[iSommet].end());
}
}
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(0);
int nbRequetes;
cin >> nbSommets >> nbAretes >> nbRequetes;
for (int i = 0; i < nbAretes; ++i) {
int u, v;
cin >> u >> v;
--u, --v;
adj[u].push_back(v);
revAdj[v].push_back(u);
}
init();
for (int iRequete = 0; iRequete < nbRequetes; ++iRequete) {
int source, nbInterdits;
cin >> source >> nbInterdits;
--source;
set<int> interdits;
for (int i = 0; i < nbInterdits; ++i) {
int u;
cin >> u;
interdits.insert(u - 1);
}
if (nbInterdits >= TRESH) {
auto dp = naiveDp(source);
int sol = -1;
for (int i = 0; i < nbSommets; ++i)
if (dp[i] > sol and !interdits.count(i))
sol = dp[i];
cout << sol << '\n';
} else {
int ret = -1;
for (int i = (int)furthest[source].size() - 1; i >= 0; --i) {
if (!interdits.count(furthest[source][i].first)) {
ret = furthest[source][i].second;
break;
}
}
cout << ret << '\n';
}
}
}
