#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vect;
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
#define pb push_back
#define f first
#define s second
const int N = 1e5 + 1;
const int sq = 200;
vector<int> graf[N];
vector<pii> merguj(vector<pii>& a, vector<pii>& b, vector<int>& odw, int tmp){
vector<pii> wyn;
int n = a.size(), m = b.size();
int i = 0, j = 0;
while(i < n && j < m && wyn.size() < sq){
while(i < n && odw[a[i].s] == tmp){
i++;
}
while(j < m && odw[b[j].s] == tmp){
j++;
}
if(i == n || j == m) break;
if(a[i].f > b[j].f){
wyn.pb({a[i].f, a[i].s});
odw[a[i].s] = tmp;
i++;
}else{
wyn.pb({b[j].f + 1, b[j].s});
odw[b[j].s] = tmp;
j++;
}
}
while(i < n && wyn.size() < sq){
while(i < n && odw[a[i].s] == tmp){
i++;
}
if(i == n) break;
wyn.pb({a[i].f, a[i].s});
odw[a[i].s] = tmp;
i++;
}
while(j < m && wyn.size() < sq){
while(j < m && odw[b[j].s] == tmp){
j++;
}
if(j == m) break;
wyn.pb({b[j].f + 1, b[j].s});
odw[b[j].s] = tmp;
j++;
}
return wyn;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
for(int i = 0; i < m; i++){
int a, b;
cin >> a >> b;
graf[b].pb(a);
}
vector<vector<pii>> best_sq(n + 1);
vector<int> odw(n + 1, 0);
int it = 1;
for(int i = 1; i <= n; i++){
for(int u : graf[i]){
best_sq[i] = merguj(best_sq[i], best_sq[u], odw, it++);
}
if(best_sq[i].size() < sq){
best_sq[i].pb({0, i});
}
}
vector<int> zak(n + 1, 0);
for(int i = 1; i <= q; i++){
int t, x;
cin >> t >> x;
for(int j = 0; j < x; j++){
int a;
cin >> a;
zak[a] = i;
}
if(x >= sq / 2){
vector<int> dp(n + 1, -1e9);
dp[t] = 0;
for(int v = t; v >= 1; v--){
for(int u : graf[v]){
dp[u] = max(dp[u], dp[v] + 1);
}
if(zak[v] == i){
dp[v] = -1;
}
}
int best = -1;
for(int v = 1; v <= t; v++){
best = max(best, dp[v]);
}
cout << best << "\n";
}else{
bool flaga = true;
for(pii a : best_sq[t]){
int val = a.f, v = a.s;
if(zak[v] != i){
cout << val << "\n";
flaga = false;
break;
}
}
if(flaga) cout << "-1\n";
}
}
// cout << "\n";
// for(int i = 1; i <= n; i++){
// cout << "i: " << i << "\n";
// for(pii a : best_sq[i]){
// cout << "v: " << a.s << " val: " << a.f << "\n";
// }
// }
return 0;
}
