/*
* Author: Nonoze
* Created: Monday 22/07/2024
*/
#include <bits/stdc++.h>
using namespace std;
#ifndef _IN_LOCAL
#define dbg(...)
#endif
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)
template<typename T> void read(T& x, bool write=0, bool write2=1) { if (write && write2) cout << x << endl; else if (write) cout << x << ' '; else cin >> x;}
template<typename T1, typename T2> void read(pair<T1, T2>& p, bool write=0, bool write2=1) { read(p.first, write, 0), read(p.second, write, 0); if (write && write2) cout << endl;}
template<typename T> void read(vector<T>& v, bool write=0) { for (auto& x : v) read(x, write, 0); if (write) cout << endl; }
template<typename T1, typename T2> void read(T1& x, T2& y, bool write=0) { read(x, write), read(y, write); if (write) cout << endl; }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z, bool write=0) { read(x, write), read(y, write), read(z, write); if (write) cout << endl; }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz, bool write=0) { read(x, write), read(y, write), read(z, write), read(zz, write); if (write) cout << endl; }
template<typename T> void print(T x) { read(x, 1); }
template<typename T1, typename T2> void print(T1 x, T2 y) { read(x, y, 1); }
template<typename T1, typename T2, typename T3> void print(T1 x, T2 y, T3 z) { read(x, y, z, 1); }
template<typename T1, typename T2, typename T3, typename T4> void print(T1 x, T2 y, T3 z, T4 zz) { read(x, y, z, zz, 1); }
#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define int long long
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=25;
void solve();
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
int tt=1;
// cin >> tt;
while(tt--) solve();
return 0;
}
int n, k, m, q;
vector<vector<int>> adj, vraiadj;
vector<vector<pair<vector<int>, int>>> queries;
vector<int> ans;
vector<bool> vis;
vector<pair<set<pair<int, int>>, map<int, int>>> memo;
vector<int> memo2;
int dp2(int u, int goal) {
if (u>goal) return -inf;
if (u == goal) return 0;
if (memo2[u] != -1) return memo2[u];
int res = -inf;
for (int v : vraiadj[u]) {
cmax(res, dp2(v, goal) + 1);
}
return memo2[u] = res;
}
int calc(vector<int> &busy, set<pair<int, int>>& s) {
set<int> busy2;
for (auto u: busy) busy2.insert(u);
for (auto u=s.rbegin(); u!=s.rend(); u++) {
if (!busy2.count(u->se)) return u->fi;
}
return -1;
}
pair<set<pair<int, int>>, map<int, int>> dp(int u) {
if (vis[u]) return {memo[u]};
vis[u]=1;
vector<pair<set<pair<int, int>>, map<int, int>>> vec; vec.pb({{{-1, u}}, {{u, -1}}});
for (auto v: adj[u]) vec.push_back(dp(v));
sort(all(vec), [](auto &a, auto &b) { return sz(a.fi)>sz(b.fi); });
for (int i=0; i<sz(vec); i++) {
for (auto x: vec[i].fi) {
x.fi++;
if (memo[u].se.count(x.se) && memo[u].se[x.se]<x.fi) memo[u].fi.erase({x.se, memo[u].se[x.se]}), memo[u].se.erase(x.se);
if (!memo[u].se.count(x.se)) memo[u].fi.insert(x), memo[u].se[x.se]=x.fi;
}
}
for (auto x: queries[u]) {
auto [a, i]=x;
ans[i]=calc(a, memo[u].fi);
}
while (sz(memo[u].fi)>330) memo[u].fi.erase(memo[u].fi.begin());
return memo[u];
}
void solve() {
read(n, m, q);
queries.resize(n), ans.resize(q), adj.resize(n), vraiadj.resize(n), vis.resize(n), memo.resize(n);
for (int i=0; i<m; i++) {
int u, v; cin >> u >> v; u--, v--;
adj[v].pb(u);
vraiadj[u].pb(v);
}
for (int i=0; i<q; i++) {
int x, y; cin >> x >> y; x--;
vector<int> a(y);
for (int j=0; j<y; j++) cin >> a[j], a[j]--;
if (y>330) {
vector<bool> busy(n, 0);
for (auto u: a) busy[u]=1;
ans[i]=-1;
memo2.clear(), memo2.resize(x+1, -1);
for (int j=0; j<=x; j++) {
if (!busy[j]) cmax(ans[i], dp2(j, x));
}
}
else queries[x].push_back({a, i});
}
for (int i=n-1; i>=0; i--) dp(i);
for (auto u: ans) cout << u << endl;
}
