#include<bits/stdc++.h>
using namespace std;
void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << h; if(sizeof...(t)) cerr << ", ";
DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL
#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;
void setIO(string NAME = "") {
cin.tie(0)->sync_with_stdio(0);
if(sz(NAME)) {
freopen((NAME + ".inp").c_str(),"r",stdin);
freopen((NAME + ".out").c_str(),"w",stdout);
}
}
const int BL = 60;
tcT> bool ckmax(T&a, const T&b) {
return b > a ? a = b, 1 : 0;
}
const int MX = 1e5+5;
const int MOD = 1e9 + 7;
int N, M, Q;
vi adj[MX];
V<array<int,2>> dp[MX];
int cst[MX];
int DP[MX];
bool vis[MX];
void solve() {
cin>>N>>M>>Q;
F0R(_,M) {
int u, v; cin>>u>>v;
adj[v].pb(u);
}
FOR(i,1,N+1) {
vi ver = {i};
each(v, adj[i]) {
each(ele, dp[v]) {
if(!cst[ele[1]])
ver.pb(ele[1]);
ckmax(cst[ele[1]], ele[0]+1);
}
}
nth_element(ver.begin(), ver.begin() + min(sz(ver), BL), ver.end(), [&](const int &a, const int &b) { return cst[a] > cst[b]; });
F0R(j,min(sz(ver), BL)) dp[i].pb({cst[ver[j]], ver[j]});
F0R(j,sz(ver)) cst[ver[j]] = 0;
}
while(Q-->0) {
int dest, nabs;
cin>>dest>>nabs;
F0R(i,nabs) {
cin>>cst[i];
vis[cst[i]] = 1;
}
int ans = -1;
if(nabs >= BL) {
FOR(i,1,dest+1) {
DP[i] = vis[i] ? -MOD : 0;
each(v, adj[i]) ckmax(DP[i], DP[v] + 1);
}
ans = DP[dest];
}
else {
F0R(i,sz(dp[dest])) if(!vis[dp[dest][i][1]]) {
ckmax(ans, dp[dest][i][0]);
}
}
F0R(i,nabs) vis[cst[i]] = 0;
cout << ans << nl;
}
}
int main() {
setIO();
int t=1;
//cin>>t;
while(t-->0) {
solve();
}
return 0;
}
