#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;
#define ordered_set <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset <int, null_type, less_equal <int>, rb_tree_tag, tree_order_statistics_node_update>
// #define int long long
#define double long double
#define pii pair <int, int>
#define tiii tuple <int, int, int>
#define tiiii tuple <int, int, int, int>
#define emb emplace_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define iShowSpeed cin.tie(NULL)->sync_with_stdio(false)
#define matrix vector <vector <int>>
#define mat(n, m) vector <vector <int>> (n, vector <int> (m));
const int mod = 1e9 + 7;
const int inf = 1e18;
const matrix II = {{1, 0}, {0, 1}};
const int N = 2e5 + 5;
void solve(){
int n, m, q; cin >> n >> m >> q; int sq = 150;
vector <int> adj[n + 1], radj[n + 1];
for (int i = 1; i <= m; i++) {
int u, v; cin >> u >> v;
adj[u].emb(v);
radj[v].emb(u);
}
vector <pii> dp[n + 1];
vector <int> visited(n + 1);
for (int u = 1; u <= n; u++) {
vector <pii> cur;
for (auto v : radj[u]) {
cur.emb(1, v);
for (auto [dis, node] : dp[v]) {
cur.emb(dis + 1, node);
}
}
sort(rall(cur));
for (auto [dis, node] : cur) {
if (visited[node] == u) continue;
visited[node] = u;
dp[u].emb(dis, node);
if (dp[u].size() == sq) break;
}
}
vector <int> cant(n + 1, inf);
int cnt = 0;
while (q--) {
int st, y; cin >> st >> y;
// cout << ++cnt << " : ";
for (int i = 1; i <= y; i++) {
int x; cin >> x;
cant[x] = q;
}
if (y <= sq) {
int ans = (cant[st] == q ? -1 : 0);
for (auto [dis, node] : dp[st]) {
if (cant[node] == q) continue;
ans = max(ans, dis);
}
// cout << "SQ : ";
cout << ans << "\n";
}
else {
vector <int> mx(n + 1, -inf);
for (int u = 1; u <= st; u++) {
if (cant[u] != q) mx[u] = 0;
for (auto v : radj[u]) {
mx[u] = max(mx[u], mx[v] + 1);
}
}
cout << (mx[st] < 0 ? -1ll : mx[st]) << "\n";
}
}
}
int32_t main(){
iShowSpeed;
// int q; cin >> q; while (q--)
solve();
}
