#include <bits/stdc++.h>
using namespace std;
const int maxn = 100000;
const int SQRTN = 330;
struct Party {
int nd;
vector<int> not_allowed;
};
int n, m, q;
vector<int> adj[maxn];
vector<int> rev[maxn];
Party parties[maxn];
vector<pair<int,int>> track[maxn]; // tracks SQRTN best
int vis[maxn]; // when merging, tracks which ones are done
int dp[maxn]; // when naive, tracks best for each one
int dpvis[maxn]; // tracks which parties not to include
int apply_naive(int party) {
int nd = parties[party].nd;
for (auto i : parties[party].not_allowed) dpvis[i] = true;
for (int i = 0; i <= nd; i++) {
dp[i] = (dpvis[i] ? -1 : 0);
for (auto j : rev[i])
dp[i] = max(dp[i], dp[j] + (dp[j] != -1));
}
for (auto i : parties[party].not_allowed) dpvis[i] = false;
return dp[nd];
}
void unite(int i, int j, vector<pair<int,int>>& fin) {
int icnt = 0, jcnt = 0;
while (fin.size() < SQRTN && (icnt < (int)track[i].size() || jcnt < (int)track[j].size())) {
if (jcnt == (int)track[j].size() || (i < (int)track[i].size() && track[i][icnt].first > track[j][jcnt].first)) {
vis[track[i][icnt].second] = 1;
fin.push_back(track[i][icnt]); icnt++;
} else {
vis[track[j][jcnt].second] = 1;
fin.push_back(track[j][jcnt]); jcnt++;
fin.back().first++;
}
while (icnt < (int)track[i].size() && vis[track[i][icnt].second]) icnt++;
while (jcnt < (int)track[j].size() && vis[track[j][jcnt].second]) jcnt++;
}
for (auto x : fin) vis[x.second] = 0;
}
void init_short() {
track[0].push_back({0, 0});
for (int i = 1; i < n; i++) {
track[i].push_back({0, i});
for (auto j : rev[i]) {
// unite track[i] with track[j]
vector<pair<int,int>> fin;
unite(i, j, fin);
swap(track[i], fin);
}
}
}
int apply_short(int party) {
int nd = parties[party].nd;
for (auto i : parties[party].not_allowed) dpvis[i] = true;
int ans = -1;
for (auto i : track[nd])
if (!dpvis[i.second]) {
ans = i.first;
break;
}
for (auto i : parties[party].not_allowed) dpvis[i] = false;
return ans;
}
int main() {
// freopen("main.in", "r", stdin);
cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int a, b; cin >> a >> b; a--, b--;
adj[a].push_back(b);
rev[b].push_back(a);
}
for (int i = 0; i < q; i++) {
cin >> parties[i].nd; parties[i].nd--;
int x; cin >> x;
while (x--) {
int b; cin >> b; b--;
parties[i].not_allowed.push_back(b);
}
}
init_short();
for (int i = 0; i < q; i++) {
if (parties[i].not_allowed.size() >= SQRTN - 1) {
cout << apply_naive(i) << endl;
} else {
cout << apply_short(i) << endl;
}
}
return 0;
}
