#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> bool cmin(T &i, T j) { return i > j ? i=j,1:0; }
template<class T> bool cmax(T &i, T j) { return i < j ? i=j,1:0; }
const int B = 90, N = 1e5;
set<pair<int,int>> longest_dist[N];
map<int,int> dist_from_node[N];
vector<int> adj[N];
int V[N],dist[N];
bool banned[N];
/*
map<int,int> start_node[N];
void dfs(int u,int d,int start) {
for (int &v: adj[u]) {
if (!start_node[u].count(start) || start_node[u][start] < d) {
start_node[u][start]=d;
if (dist[v].size() == B) {
if (*dist[v].begin() < d) {
dist[v].erase(dist[v].begin());
dist[v].insert(d);
dfs(v,d+1,start);
}
} else {
dist[v].insert(d);
dfs(v,d+1,start);
}
}
}
}
*/
void solve() {
int n,m,q;
cin >> n >> m >> q;
for (int u,v;m--;) {
cin >> u >> v;
assert(u < v);
adj[--u].push_back(--v);
}
for (int i=0;i<n;i++) {
if (longest_dist[i].size() != B) {
longest_dist[i].insert(make_pair(0,i));
}
for (int &v: adj[i]) {
for (auto it = longest_dist[i].begin();it != longest_dist[i].end();it++) {
pair<int,int> C = *it;
C.first++;
if (!dist_from_node[v].count(C.second) ||
dist_from_node[v][C.second] < C.first) {
if (dist_from_node[v].count(C.second)) {
longest_dist[v].erase(make_pair(dist_from_node[v][C.second],
C.second));
}
dist_from_node[v][C.second]=C.first;
if (longest_dist[v].size() == B) {
if ((*longest_dist[v].begin()).first < C.first) {
longest_dist[v].erase(longest_dist[v].begin());
longest_dist[v].insert(C);
}
} else {
longest_dist[v].insert(C);
}
}
}
}
}
for (int u,sz;q--;) {
cin >> u >> sz;
--u;
for (int i=0;i<sz;i++) {
cin >> V[i];
banned[--V[i]]=true;
}
if (sz >= int(longest_dist[u].size())) {
memset(dist,-1,4*(u+1));
for (int i=0;i<=u;i++) {
if (!banned[i]) {
cmax(dist[i],0);
}
if (dist[i] != -1) {
// this node CAN be reached
for (int &v: adj[i]) {
cmax(dist[v],dist[u]+1);
}
}
}
cout << dist[u] << "\n";
} else {
auto it = longest_dist[u].end();
while(true) {
assert(it != longest_dist[u].begin());
it--;
if (!banned[(*it).second]) { cout << (*it).first << "\n"; break; }
}
}
for (int i=0;i<sz;i++) {
banned[V[i]]=false;
}
}
/*
for (int i=0;i<n;i++) {
cout << "Node " << i << "\n";
for (auto [d,node]: longest_dist[i]) {
cout << "Dist " << d << " from node " << node << "\n";
}
cout << "\n";
}
*/
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int _t = 1;
for (int i=1;i<=_t;i++) {
solve();
}
}
