#include <bits/stdc++.h>
using namespace std;
#define debug(x) {cout << #x << ": "; for (auto it : x) cout << it << " ";cout << endl;}
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define MOD 1000000007
#define LOGN 15
#define MAXN 100005
const int SQRT = 300;
vector<vector<int>> graph, rev;
vector<vector<pair<int,int>>> dist;
bool closed[MAXN], taken[MAXN];
void get(int to, int from) {
int sz_to = dist[to].size();
int sz_from = dist[from].size();
int t_i = sz_to - 1, f_i = sz_from - 1;
vector<pair<int,int>> new_l;
while (new_l.size() < SQRT && (f_i >= 0 || t_i >= 0)) {
pair<int,int> now = {-1, -1};
if (f_i >= 0 && dist[from][f_i].s + 1 >= now.s)
now = {dist[from][f_i].f, dist[from][f_i].s + 1};
if (t_i >= 0 && dist[to][t_i].s >= now.s)
now = dist[to][t_i];
if (!taken[now.f]) {
new_l.push_back(now);
taken[now.f] = true;
}
while (t_i >= 0 && dist[to][t_i].f == now.f)
t_i--;
while (f_i >= 0 && dist[from][f_i].f == now.f)
f_i--;
}
reverse(new_l.begin(), new_l.end());
dist[to] = new_l;
for (auto u : new_l)
taken[u.f] = false;
}
int main() {
fast
int N, M, Q, S, E;
cin >> N >> M >> Q;
graph = vector<vector<int>>(N+1, vector<int>());
rev = vector<vector<int>>(N+1, vector<int>());
dist = vector<vector<pair<int,int>>>(N+1, vector<pair<int,int>>());
for (int i = 0; i < M; i++) {
cin >> S >> E;
graph[S].push_back(E);
rev[E].push_back(S);
}
for (int i = 1; i <= N; i++)
dist[i].push_back({i, 0});
for (int i = 1; i <= N; i++) {
for (auto u : graph[i])
get(u, i);
}
while (Q--) {
int town, cnt;
cin >> town >> cnt;
vector<int> towns(cnt);
for (int i = 0; i < cnt; i++) {
cin >> towns[i];
closed[towns[i]] = true;
}
int ans = -1;
if (cnt >= SQRT) {
vector<int> new_dist(N+1, -1e8);
new_dist[town] = 0;
for (int i = town; i >= 1; i--) {
if (new_dist[i] < 0)
continue ;
for (auto u : rev[i])
new_dist[u] = max(new_dist[u], new_dist[i] + 1);
}
for (int i = 1; i <= town; i++) {
if (!closed[i])
ans = max(ans, new_dist[i]);
}
} else {
for (auto u : dist[town]) {
if (!closed[u.f])
ans = max(ans, u.s);
}
}
cout << ans << "\n";
for (auto u : towns)
closed[u] = false;
}
}
