#include <bits/stdc++.h>
#define mid ((l+r)>>1)
using namespace std;
vector<int> vc[200005];
vector<pair<int, int>> nr[200005];
int B = 150;
int ok[200005], dist[200005], tag[200005];
signed main() {
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
int n, m, q; cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int u, v; cin >> u >> v;
vc[u].push_back(v);
}
for (int i = 1; i <= n; i++) {
if (nr[i].size() < B) {
nr[i].push_back(make_pair(0, i));
}
for (auto v : vc[i]) {
vector<pair<int, int>> nw;
int it1 = 0, it2 = 0;
while (((it1 != nr[i].size()) || (it2 != nr[v].size())) && (nw.size() < B)) {
if (it1 == nr[i].size()) {
if (tag[nr[v][it2].second]) {
it2++;
continue;
} tag[nr[v][it2].second] = 1;
nw.push_back(nr[v][it2]);
it2++;
continue;
}
if (it2 == nr[v].size()) {
if (tag[nr[i][it1].second]) {
it1++;
continue;
} tag[nr[i][it1].second] = 1;
auto t = nr[i][it1];
t.first++;
nw.push_back(t);
it1++;
continue;
}
if (nr[i][it1].first + 1 > nr[v][it2].first) {
if (tag[nr[i][it1].second]) {
it1++;
continue;
} tag[nr[i][it1].second] = 1;
auto t = nr[i][it1];
t.first++;
nw.push_back(t);
it1++;
continue;
}
else {
if (tag[nr[v][it2].second]) {
it2++;
continue;
} tag[nr[v][it2].second] = 1;
nw.push_back(nr[v][it2]);
it2++;
continue;
}
}
swap(nw, nr[v]);
nw.clear();
for (auto u : nr[v]) tag[u.second] = 0;
}
}
// for(int i=1;i<=n;i++,cout<<"\n") for(auto v:nr[i]) cout<<v.first<<" "<<v.second<<" ";
while (q--) {
int s, k; cin >> s >> k;
if (k >= 150) {
for (int i = 1; i <= n; i++) ok[i] = 1, dist[i] = -1;
while (k--) {
int x; cin >> x; ok[x] = 0;
}
for (int i = 1; i <= n; i++) {
if (ok[i]) dist[i] = max(dist[i], 0);
if (dist[i] >= 0) {
for (auto v : vc[i]) {
dist[v] = max(dist[v], dist[i] + 1);
}
}
}
cout << dist[s] << "\n";
}
else {
vector<int> nd;
while (k--) {
int x; cin >> x; nd.push_back(x);
}
for (auto v : nd) tag[v] = 1;
int maxv = -1;
for (auto v : nr[s]) {
if (!tag[v.second]) {
maxv = v.first;
break;
}
}
for (auto v : nd) tag[v] = 0;
cout << maxv << "\n";
}
}
return 0;
}
