#include <bits/stdc++.h>
#define int long long
#define emb emplace_back
#define pii pair <int, int>
using namespace std;
const int mod = 1e9 + 7;
const int inf = 1e18;
signed main(){
cin.tie(NULL)->sync_with_stdio(false);
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;
int stidx[n + 1]; memset(stidx, 0, sizeof stidx);
for (int u = 1; u <= n; u++) {
priority_queue <tuple <int, int, int, int>> pq;
for (auto v : rev[u]) {
pq.emplace(1, -v, 0, v);
if (dp[v][1].first != -1) pq.emplace(dp[v][1].first + 1, -dp[v][1].second, 1, v);
}
id++;
for (int i = 1; i <= sq; i++) {
while (!pq.empty() && visited[-get <1> (pq.top())] == id) {
int root = get <3> (pq.top());
int nowidx = get <2> (pq.top());
pq.pop();
if (nowidx == 0) continue;
if (nowidx != sq && dp[root][nowidx + 1].first != -1) pq.emplace(dp[root][nowidx + 1].first + 1, -dp[root][nowidx + 1].second, nowidx + 1, root);
}
if (pq.empty()) break;
dp[u][i] = {get <0> (pq.top()), -get <1> (pq.top())};
visited[-get <1> (pq.top())] = id;
int root = get <3> (pq.top());
int nowidx = get <2> (pq.top());
pq.pop();
if (nowidx == 0) continue;
if (nowidx != sq && dp[root][nowidx + 1].first != -1) pq.emplace(dp[root][nowidx + 1].first + 1, -dp[root][nowidx + 1].second, nowidx + 1, root);
}
}
// for (int i = 1; i <= n; i++) {
// cout << i << ": " << "\n";
// for (int j = 1; j <= sq; j++) {
// if (dp[i][j].first == -1) break;
// cout << i << ", " << j << " = " << dp[i][j].first << ", " << dp[i][j].second << "\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--) {
if (i != u) {
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";
}
}
