#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize("fast-math")
#define ll long long
#define ld long double
#define vi vector<ll>
#define endl "\n"
#define pr pair<ll, ll>
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
const int mod = 1e9+7;
void _p(ll a){cout<<a<<endl;}
void _p(string a){cout<<a<<endl;}
void _p(ld a) {cout<<a<<endl;}
template <class T>
void _p(vector<T> a){for(T val:a)cout<<val<<" ";cout<<endl;}
#define debug(x) cout<<#x<<" -> ";_p(x)
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
vector<pr> move8 = {{1, 0}, {1, 1}, {0, 1}, {-1, 1}, {-1, 0}, {-1, -1}, {0, -1}, {1, -1}};
vector<pr> move4 = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
vector<pr> move2 = {{0, 1}, {1, 0}};
void solution();
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solution();
return 0;
}
const int MAXN = 1e5+10;
bool vis[MAXN];
vi adj[MAXN];
vi radj[MAXN];
ll n, m, q;
ll B;
vector<set<pr>> PDist;
vi ord;
void dfs(ll a) {
vis[a] = true;
for (auto b : adj[a]) {
if (vis[b]) continue;
dfs(b);
}
ord.push_back(a);
}
ll calculate(ll T, set<ll> &temp) {
vi dist(n+1);
for (auto val : temp) dist[val] = -1;
for (auto a : ord) {
for (auto b : radj[a]) {
if (dist[b] == -1) continue;
dist[a] = max(dist[b] + 1, dist[a]);
}
if (a == T) break;
}
return dist[T];
}
void precomputation() {
priority_queue<array<ll, 3>> q;
for (int i = 1; i <= n; i++) {
q.push({0, i, i});
}
while (!q.empty()){
auto [d, a, h] = q.top(); q.pop();
if (PDist[a].size() > B+1 &&
PDist[a].begin()->ff > d) continue;
PDist[a].insert({d, h});
if (PDist[a].size() > B+1) PDist[a].erase(PDist[a].begin());
for (auto b : adj[a]) {
q.push({d+1, b, h});
}
}
}
void solution() {
cin >> n >> m >> q;
B = sqrt(n);
PDist.resize(n+1);
while (m--) {
ll a, b; cin >> a >> b;
adj[a].push_back(b);
radj[b].push_back(a);
}
for (int i = 1; i <= n; i++) {
if (!vis[i]) dfs(i);
}
reverse(all(ord));
precomputation();
while (q--) {
ll T, Y;
cin >> T >> Y;
set<ll> temp;
for (int i = 0; i < Y; i++) {
ll x; cin >> x; temp.insert(x);
}
if (Y >= B) {
cout << calculate(T, temp) << endl;
} else {
ll ans = -1;
for (auto [x, y] : PDist[T]) {
if (temp.count(y)) continue;
ans = max(ans, x);
}
cout << ans << endl;
}
}
}
