#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5;
const int TRESH = 200;
vector<int> adj[MAXN];
bitset<MAXN> seen;
vector<int> revAdj[MAXN];
vector<pair<int, int>> furthest[MAXN];
int buffer[MAXN];
int nbSommets, nbAretes;
int dp[MAXN];
void naiveDp(int source) {
for (int i = 0; i < nbSommets; ++i)
dp[i] = -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);
}
void init() {
auto combine = [&](const vector<pair<int, int>> &lft,
const vector<pair<int, int>> &rgt) {
vector<pair<int, int>> ret;
int lftSize = lft.size(), rgtSize = rgt.size();
ret.reserve(min(lftSize + rgtSize, TRESH));
int posDel = 0;
int posLft = 0, posRgt = 0;
for (int i = 0;
(posLft < lftSize or posRgt < rgtSize) and (int) ret.size() < TRESH;
++i) {
if (posLft < lftSize and seen[lft[posLft].first]) {
++posLft;
continue;
}
if (posRgt < rgtSize and seen[rgt[posRgt].first]) {
++posRgt;
continue;
}
if (posRgt == rgtSize or
(posLft < lftSize and lft[posLft].second > rgt[posRgt].second)) {
buffer[posDel++] = lft[posLft].first;
seen[lft[posLft].first] = true;
ret.push_back(lft[posLft++]);
} else {
buffer[posDel++] = rgt[posRgt].first;
seen[rgt[posRgt].first] = true;
ret.push_back(rgt[posRgt++]);
}
}
while (posDel > 0)
seen[buffer[--posDel]] = false;
return ret;
};
for (int iSommet = 0; iSommet < nbSommets; ++iSommet) {
vector<pair<int, int>> cur;
for (int iPere : revAdj[iSommet])
cur = combine(cur, furthest[iPere]);
for (auto &[u, d] : cur)
d++;
if ((int)cur.size() < TRESH)
cur.emplace_back(iSommet, 0);
furthest[iSommet] = move(cur);
}
}
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);
}
assert((int)interdits.size() == nbInterdits);
if (nbInterdits >= TRESH) {
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;
assert(interdits.size() < TRESH);
for (int i = 0; i < (int)furthest[source].size(); ++i)
if (!interdits.count(furthest[source][i].first)) {
ret = furthest[source][i].second;
break;
}
cout << ret << '\n';
}
}
}
