#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
struct pair_hash{
size_t operator()(const pair<int,int>&x)const{
return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32));
}
};
const int INF = 1e9;
const int MAXN = 1e5 + 7;
const int B = 267;
vi g[MAXN];
vector<pii> best[MAXN];
int blocked[MAXN];
int added[MAXN];
int dist[MAXN];
int n, m, q;
void preprocessing(){
for(int i = 1; i <= n; i++){
best[i].pb(mp(0, i));
for(auto u : g[i]){
vector<pii> merged = {};
int wsk1 = 0;
int wsk2 = 0;
while(sz(merged) < B && (wsk1 < sz(best[i]) || wsk2 < sz(best[u]))){
if(wsk1 == sz(best[i])){
if(!added[best[u][wsk2].se]){
merged.pb(mp(best[u][wsk2].fi + 1, best[u][wsk2].se));
added[best[u][wsk2].se] = 1;
}
wsk2++;
}else if(wsk2 == sz(best[u])){
if(!added[best[i][wsk1].se]){
merged.pb(mp(best[i][wsk1].fi, best[i][wsk1].se));
added[best[i][wsk1].se] = 1;
}
wsk1++;
}else{
if(best[u][wsk2].fi + 1 >= best[i][wsk1].fi){
if(!added[best[u][wsk2].se]){
added[best[u][wsk2].se] = 1;
merged.pb(mp(best[u][wsk2].fi + 1, best[u][wsk2].se));
}
wsk2++;
}else{
if(!added[best[i][wsk1].se]){
merged.pb(mp(best[i][wsk1].fi, best[i][wsk1].se));
added[best[i][wsk1].se] = 1;
}
wsk1++;
}
}
}
best[i] = merged;
for(auto ele : merged){
added[ele.se] = 0;
}
}
//debug(best[i]);
}
}
int solveBig(int v){
for(int i = 1; i <= v; i++){
if(blocked[i]){
dist[i] = -INF;
}else{
dist[i] = 0;
}
for(auto u : g[i]){
if(dist[u] != -INF){
dist[i] = max(dist[i], dist[u] + 1);
}
}
}
if(dist[v] == -INF){
return -1;
}
return dist[v];
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> m >> q;
for(int i = 1; i <= m; i++){
int a, b;
cin >> a >> b;
g[b].pb(a);
}
preprocessing();
while(q--){
int v, l;
cin >> v >> l;
vi curr(l);
for(int i = 0; i < l; i++){
cin >> curr[i];
blocked[curr[i]] = 1;
}
if(l >= B){
cout << solveBig(v) << '\n';
}else{
int ans = -1;
for(auto ele : best[v]){
if(!blocked[ele.se]){
ans = max(ans, ele.fi);
}
}
cout << ans << '\n';
}
for(auto ele : curr){
blocked[ele] = 0;
}
}
return 0;
}
