#include <bits/stdc++.h>
using namespace std;
#define fod(i,a,b) for(int i((int) (a)), _b(b); i <= _b; i++)
#define fok(i,a,b) for(int i((int) (a)), _b(b); i >= _b; i--)
#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define fi first
#define se second
#define ve vector
#define vi ve<int>
#define vll ve<ll>
#define el '\n'
#define mask(i) (1LL<<(i))
#define BIT(msk,i) (msk>>(i)&1LL)
template<class T> bool mini(T &a, T b){ return (a > (b) ? a = (b), 1 : 0); }
template<class T> bool maxi(T &a, T b){ return (a < (b) ? a = (b), 1 : 0); }
const int base = mask(20) + 5;
#define name "bitaro_party"
int n, m, q;
const int N = 1e5;
const int M = 2e5;
const int Q = 1e5;
const int SQRTN = 100;
ve <vi> g;
int dp[N + 5];
namespace sub1{
bool check(){
return (n <= 1000 and m <= 2000) or q == 1;
}
int host, num;
void solve(){
while(q--){
cin >> host >> num;
fod(i,1,host) dp[i] = 0;
fod(i,1,num){
int x; cin >> x;
dp[x] = -1e9;
}
fod(i,1,host){
for(int j : g[i]){
maxi(dp[i], dp[j] + 1);
}
}
cout << max(dp[host], -1) << el;
}
}
}
namespace sub2{
int dis[N + 5];
ve <pii> f[N + 5];
int host, num;
int cant[N + 5];
bool del[N + 5];
int solve_light(){
for(pii x : f[host]) if(!del[x.se]) return x.fi;
return -1;
}
int solve_heavy(){
fod(i,1,host) dp[i] = 0;
fod(i,1,num) dp[cant[i]] = -1e9;
fod(i,1,host){
for(int j : g[i]){
maxi(dp[i], dp[j] + 1);
}
}
return max(dp[host], -1);
}
void solve(){
fod(i,1,n){
bitset <N+5> vst;
for(int j : g[i]){
for(pii path : f[j]){
maxi(dis[path.se], path.fi);
vst.set(path.se);
}
}
f[i].pb(mp(0, i));
for(int x = vst._Find_first(); x < (int)vst.size(); x = vst._Find_next(x)){
f[i].pb(mp(dis[x] + 1, x));
dis[x] = -1;
}
sort(f[i].begin(), f[i].end(), greater<pii>());
while((int) f[i].size() > SQRTN) f[i].pop_back();
}
while(q--){
cin >> host >> num;
fod(i,1,num) cin >> cant[i];
fod(i,1,num) del[cant[i]] = 1;
if(num < SQRTN) cout << solve_light() << el;
else cout << solve_heavy() << el;
fod(i,1,num) del[cant[i]] = 0;
}
}
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
if(fopen(name".inp", "r")){
freopen(name".inp", "r", stdin);
freopen(name".out", "w", stdout);
}
cin >> n >> m >> q;
{
int u, v;
g.resize(n + 1);
fod(i,1,m){
cin >> u >> v;
g[v].pb(u);
}
}
fod(i,1,n) sort(g[i].begin(), g[i].end());
if(sub1 :: check()) sub1 :: solve();
else sub2 :: solve();
return 0;
}
