#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double
const int MAXN = 1e5;
const ll INF = 4e18;
const int MOD = 998244353;
ll dp[MAXN + 5], ans[MAXN + 5];
vector<ll> adj[MAXN + 5];
bitset<100005> bd;
struct DSU{
ll N;
vector<ll> par;
DSU(ll _n){
N = _n;
par.resize(N + 5);
iota(par.begin(), par.end(), 0LL);
}
ll find(ll idx){
return par[idx] == idx ? idx : par[idx] = find(par[idx]);
}
void join(ll a, ll b){
a = find(a), b = find(b);
if(a == b) return;
par[b] = a;
}
};
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll N, M, Q; cin >> N >> M >> Q;
vector<ll> adj[N + 5];
for(int i = 1; i <= M; i++){
ll u, v; cin >> u >> v;
adj[v].push_back(u);
}
DSU dsu(N);
vector<ll> queries[N + 5], C[Q + 5];
for(int i = 1; i <= Q; i++){
ll T; cin >> T;
queries[T].push_back(i);
ll X; cin >> X;
for(int j = 1; j <= X; j++){
ll val; cin >> val;
C[i].push_back(val);
}
}
for(int i = 1; i <= N; i++){
for(auto j : adj[i]){
dp[i] = max(dp[i], dp[j] + 1);
dsu.join(i, j);
}
for(auto j : queries[i]){
for(auto x : C[j]) bd[x] = 1;
ans[j] = -1;
for(int k = 1; k <= N; k++){
if(dsu.find(i) == dsu.find(k) && !bd[k]) ans[j] = max(ans[j], dp[i] - dp[k]);
}
for(auto x : C[j]) bd[x] = 0;
}
}
for(int i = 1; i <= Q; i++) cout << ans[i] << "\n";
}
}
/*
*/
