#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}};
int32_t main(){
iShowSpeed;
int n, m, q; cin >> n >> m >> q; int sq = sqrt(n); sq++;
vector <int> adj[n + 1], rev[n + 1];
for (int i = 1; i <= m; i++) {
int u, v; cin >> u >> v;
adj[u].emb(v);
rev[v].emb(u);
}
pii dp[n + 5][sq + 5];
for (int i = 1; i <= n; i++) for (int j = 1; j <= sq; j++) dp[i][j] = {-1, -1};
int visited[n + 1]; memset(visited, 0, sizeof visited);
int id = 0;
for (int u = 1; u <= n; u++) {
// cout << u << ": \n";
priority_queue <pii> pq;
for (auto v : rev[u]) {
pq.emplace(1, v);
// cout << v << " = " << 1 << "\n";
for (int i = 1; i <= sq; i++) {
auto [dis, node] = dp[v][i];
if (dis == -1) break;
pq.emplace(dis + 1, node);
// cout << node << " = " << dis + 1 << "\n";
}
}
id++;
for (int i = 1; i <= sq; i++) {
while (!pq.empty() && visited[pq.top().second] == id) pq.pop();
if (pq.empty()) break;
// cout << pq.top().second << " -> " << u << ": " << pq.top().first << "\n";
dp[u][i] = pq.top();
visited[pq.top().second] = id;
pq.pop();
}
// cout << "-------------------\n";
}
// for (int i = 1; i <= n; i++) {
// for (int j = 1; j <= sq; j++) {
// auto [dis, node] = dp[i][j];
// cout << i << ": " << j << " = " << "[" << dis << ", " << node << "]\n";
// }
// cout << "-----------------------\n";
// }
int idx = 0;
int cant[n + 1]; memset(cant, 0, sizeof cant);
int cal[n + 1], cali[n + 1];
memset(cal, -1, sizeof cal);
memset(cali, -1, sizeof cali);
while (q--) {
idx++;
int u, cnt; cin >> u >> cnt;
for (int i = 1; i <= cnt; i++) {
int x; cin >> x;
cant[x] = idx;
}
int ans = (cant[u] == idx ? -1 : 0);
if (cnt < sq) {
for (int i = 1; i <= sq; i++) {
auto [dis, node] = dp[u][i];
if (node == -1) break;
// cout << dis << ", " << node << "\n";
if (cant[node] == idx) continue;
ans = dis;
break;
}
}
else {
cal[u] = 0;
cali[u] = idx;
for (int i = u; i >= 1; i--) {
cal[i] = -1;
for (auto v : adj[i]) {
if (cali[v] == idx) cal[i] = max(cal[i], cal[v] + 1);
}
if (cal[i] != -1) cali[i] = idx;
if (cant[i] != idx) ans = max(ans, cal[i]);
}
}
cout << ans << "\n";
}
}
