// #pragma GCC optimize ("Ofast")
// #pragma GCC target ("avx,avx2")
// #pragma GCC optimize("unroll-loops")
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#include <unordered_map>
#include <unordered_set>
#define ll long long
#define ld long double
#define pl pair<ll, ll>
#define vi vector<ll>
#define vii vector<vi>
#define vc vector<char>
#define vcc vector<vc>
#define vp vector<pl>
#define mi map<ll,ll>
#define mc map<char,int>
#define sortx(X) sort(X.begin(),X.end());
#define all(X) X.begin(),X.end()
#define allr(X) X.rbegin(),X.rend()
#define ln '\n'
#define YES {cout << "YES\n"; return;}
#define NO {cout << "NO\n"; return;}
#define MUN {cout << "-1\n"; return;}
const int MODE = 998244353;
const int MOD2 = (MODE + 1) / 2;
using namespace std;
const ll INF = 1e16;
const ll sq = 120;
void solve(int tc) {
ll n, m, q;
cin >> n >> m >> q;
vii adj(n+1);
vii radj(n+1);
for (int i = 0; i < m; i++)
{
ll u, v; cin >> u >> v;
if (u > v) swap(u, v);
adj[u].push_back(v);
radj[v].push_back(u);
}
vector<vp> dp(n+1);
for (int i = 0; i <= n; i++)
{
dp[i].push_back({0, i});
}
vi vis(n+1);
vi ord;
function<void(ll)> dfs = [&](ll u) {
if (vis[u]) return;
vis[u] = 1;
for (auto neg : adj[u]) {
dfs(neg);
}
ord.push_back(u);
};
for (int i = 1; i <= n; i++) dfs(i);
reverse(all(ord));
for (auto u : ord) {
sortx(dp[u]);
while (dp[u].size()>sq) dp[u].pop_back();
for (auto a : dp[u]) {
a.first--;
for (auto neg : adj[u]) {
dp[neg].push_back(a);
}
}
}
swap(adj, radj);
while (q--)
{
ll t, k; cin >> t >> k;
vi Y(k);
for (int i = 0; i < k; i++) cin >> Y[i];
sortx(Y);
if (k < sq - 1) {
for (auto [a, b] : dp[t]) {
if (!binary_search(all(Y), b)) {
cout << -a << '\n';
goto EE;
}
}
cout << "-1\n";
} else {
ord.clear();
vis.assign(n+1, 0);
dfs(t); // dfs uses adj (predecessors after swap)
vi V(n+1, -INF);
vi in(n+1, 1);
for (auto a : Y) in[a] = 0;
for (auto u : ord) {
if (in[u]) V[u] = 0; // can start here
// else keep -INF (can't start here)
for (auto pred : adj[u]) { // adj = predecessors after swap
if (V[pred] > -INF/2)
V[u] = max(V[u], V[pred] + 1);
}
}
ll ans = V[t];
if (ans < 0) ans = -1;
cout << ans << '\n';
}
EE:;
}
}
int main()
{
ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int size = 1;
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
// cin >> size;
for (int i = 1; i <= size; i++) solve(i);
}
