#include <bits/stdc++.h>
#define maxn 100010
using namespace std;
const int B = 320;
int n, m, q;
typedef pair<int, int> pi;
vector<int> prv[maxn];
set<pi> top[maxn];
set<pi> pot[maxn];
void add(pi p, int i){
set<pi>::iterator q = pot[i].lower_bound(make_pair(p.second, 0));
if (q != pot[i].end() && q -> first == p.second){
p = max(p, make_pair(q -> second, q -> first));
pot[i].erase(q);
pot[i].insert(make_pair(p.second, p.first));
top[i].erase(make_pair(q -> second, q -> first));
top[i].insert(p);
} else{
if (top[i].size() < B){
top[i].insert(p);
pot[i].insert(make_pair(p.second, p.first));
} else{
if (top[i].begin() -> first < p.first){
top[i].erase(top[i].begin());
top[i].insert(p);
pot[i].insert(make_pair(p.second, p.first));
}
}
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> q;
for (int i = 0; i < m; i ++){
int x, y;
cin >> x >> y;
x --; y --;
prv[y].push_back(x);
}
for (int i = 0; i < n; i ++){
top[i].insert(make_pair(0, i));
pot[i].insert(make_pair(i, 0));
}
for (int i = 0; i < n; i ++){
for (int j = 0; j < (int)prv[i].size(); j ++){
int x = prv[i][j];
for (set<pi>::iterator it = top[x].begin(); it != top[x].end(); it ++){
add(make_pair(it -> first + 1, it -> second), i);
}
add(make_pair(1, x), i);
}
}
while(q --){
int t; cin >> t; t --;
int r; cin >> r;
set<int> y;
for (int i = 0; i < r; i ++){
int p; cin >> p; p --;
y.insert(p);
}
if (r >= B){
vector<int> dp(n, -1);
for (int i = 0; i < n; i ++){
if (y.find(i) == y.end()){
dp[i] = max(dp[i], 0);
}
for (int j = 0; j < (int)prv[i].size(); j ++){
if (dp[prv[i][j]] != -1) dp[i] = max(dp[i], dp[prv[i][j]] + 1);
}
}
cout << dp[t] << '\n';
} else{
for (set<pi>::reverse_iterator it = top[t].rbegin(); it != top[t].rend(); it ++){
if (y.find(it -> second) == y.end()){
cout << it -> first << '\n';
goto done;
}
}
cout << -1 << '\n';
done: continue;
}
}
}
