#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
#define md ((l+r)>>1)
#define lf (id<<1)
#define rg ((id<<1)|1)
using namespace std;
typedef pair<ll,ll> pii;
typedef pair<pii,ll> ipii;
const int MAXN = 3e5+10;
const ll INF = 2e18+10;
const ll LOG = 61;
const int SQRT = 1e5+10;
const int MOD = 998244353;
int n, m, q;
vector <int> adj[MAXN];
vector <pii> best[MAXN], que;
vector <int> vec[MAXN];
int ans;
int busy[MAXN], vis[MAXN];
int day, day2;
void dfs(int nw, int dis){
if(busy[nw] != day) ans = max(ans, dis);
vis[nw] = day2;
for(auto nx : adj[nw]){
if(vis[nx] != day2) dfs(nx, dis+1);
}
}
signed main() {
cin >> n >> m >> q;
for(int i=1; i<=m; i++){
int u, v; cin >> u >> v;
adj[v].pb(u);
}
for(int i=1; i<=n; i++){
vector <pii> coba;
coba.pb({0, i});
for(auto nx : adj[i]){
for(auto in : best[nx]) coba.pb({in.fi+1, in.se});
}
sort(coba.rbegin(), coba.rend());
day++;
for(auto in : coba){
if(busy[in.se] == day) continue;
busy[in.se] = day;
best[i].pb(in);
if(best[i].size() == SQRT) break;
}
}
// for(int i=1; i<=n; i++){
// cout << "\ni" << i << "\n";
// for(auto in:best[i]) cout << in.fi << ' ' << in.se << '\n';
// }
// exit(0);
for(int i=1; i<=q; i++){
int sta, siz; cin >> sta >> siz;
ans = -1;
for(int j=0; j<siz; j++){
int x; cin >> x;
vec[i].pb(x);
}
if(siz >= SQRT){
day++; day2++;
for(auto in : vec[i]) busy[in] = day;
dfs(sta, 0);
} else {
day++;
for(auto in : vec[i]) busy[in] = day;
for(auto in : best[sta]){
if(busy[in.se] == day) continue;
ans = in.fi;
break;
}
}
cout << ans << '\n';
}
}
