#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;
#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())
const int mn = 1e5 + 5;
const int srt = 310;
struct query {
int id;
vector<int> block;
query() : id(0) {}
query (int x, vector<int> v) : id(x), block(v) {}
};
vector<int> adj[mn], rev[mn], line, lineRev;
bool vis[mn], check[mn];
void dfs (int u) {
if (vis[u]) return;
vis[u] = 1;
for (int v : adj[u]) dfs(v);
line.push_back(u);
}
void dfsRev (int u) {
if (vis[u]) return;
vis[u] = 1;
for (int v : rev[u]) dfsRev(v);
lineRev.push_back(u);
}
vector<query> qry[mn];
vector<pii> best[mn];
int dp[mn], ans[mn], iter[mn], n;
bool compare (pii a, pii b) { return a.first > b.first; }
void process (int u) {
int cnt = 0;
for (int v : rev[u]) {
if (best[v].size()) cnt++;
iter[v] = 0;
}
while (cnt && best[u].size() < srt) {
int ans = INT_MIN, save = 0;
for (int v : rev[u]) {
if (iter[v] == best[v].size()) continue;
while (iter[v] < best[v].size() && check[best[v][iter[v]].second])
iter[v]++;
if (iter[v] == best[v].size()) {
cnt--;
continue;
}
int dist, node; tie(dist, node) = best[v][iter[v]];
if (dist + 1 > ans) ans = dist + 1, save = v;
}
int dist, node; tie(dist, node) = best[save][iter[save]++];
best[u].push_back(make_pair(dist + 1, node));
check[node] = 1;
if (iter[save] == best[save].size()) cnt--;
}
if (best[u].size() < srt)
best[u].push_back(make_pair(0, u));
for (pii it : best[u]) check[it.second] = 0;
}
int dpCalc (int st, vector<int> &block) {
for (int u : block) check[u] = 1;
for (int i = 1; i <= n; i++) dp[i] = INT_MIN;
dp[st] = 0; int ans = INT_MIN;
for (int u : lineRev) {
for (int v : adj[u])
if (dp[v] != INT_MIN) dp[u] = max(dp[u], dp[v] + 1);
if (!check[u]) ans = max(ans, dp[u]);
}
for (int u : block) check[u] = 0;
return ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int m, q; cin >> n >> m >> q;
while (m--) {
int a, b; cin >> a >> b;
adj[a].push_back(b);
rev[b].push_back(a);
}
// prepare topological sorting
for (int i = 1; i <= n; i++) dfs(i);
for (int i = 1; i <= n; i++) vis[i] = 0;
for (int i = 1; i <= n; i++) dfsRev(i);
reverse(all(line)); reverse(all(lineRev));
// read queries and process big ones
for (int i = 0; i < q; i++) {
int v, k; cin >> v >> k;
vector<int> vec(k);
for (int j = 0; j < k; j++) cin >> vec[j];
if (k < srt)
qry[v].push_back(query(i, vec));
else ans[i] = dpCalc(v, vec);
}
// process small queries
for (int u : line) {
process(u);
for (query &it : qry[u]) {
for (int node : it.block) check[node] = 1;
bool ready = 0;
for (pii iter : best[u]) {
if (check[iter.second]) continue;
ans[it.id] = iter.first, ready = 1;
break;
}
if (!ready) ans[it.id] = INT_MIN;
for (int node : it.block) check[node] = 0;
}
}
// print answers
for (int i = 0; i < q; i++) cout << (ans[i] == INT_MIN ? -1 : ans[i]) << "\n";
return 0;
}
