#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5, sq = 320, INF = 1e9;
int n, m;
vector<int> adj[maxn], radj[maxn];
bool on[maxn];
vector<int> solve() {
int left[n+1];
queue<int> q;
vector<int> ans(n+1);
for (int i=1;i<=n;i++) {
left[i] = adj[i].size();
if (!left[i]) q.push(i);
}
while (q.size()) {
int u = q.front();
q.pop();
ans[u] = 0;
for (int v:adj[u]) if (on[v] || ans[v]) ans[u] = max(ans[v] + 1, ans[u]);
for (int v:radj[u]) {
left[v]--;
if (!left[v]) q.push(v);
}
}
return ans;
}
vector<int> ori_ans;
vector<pair<int,int>> vec[maxn];
int mn[maxn];
bool cmp(pair<int,int> x, pair<int,int> y) {
return mn[x.first] < mn[y.first];
}
void pre() {
int left[n+1];
queue<int> q;
for (int i=1;i<=n;i++) {
left[i] = adj[i].size();
if (!left[i]) q.push(i);
}
while (q.size()) {
int u = q.front();
q.pop();
vec[u].push_back({u, 0});
mn[u] = ori_ans[u] + 1;
for (int v:adj[u]) for (auto [x, y]:vec[v]) mn[x] = INF;
for (int v:adj[u]) {
for (auto [x, y]:vec[v]) {
mn[x] = min(ori_ans[u] - ori_ans[v] - 1 + y, mn[x]);
vec[u].push_back({x, 0});
}
}
sort(vec[u].begin(), vec[u].end(), cmp);
vec[u].erase(unique(vec[u].begin(), vec[u].end()), vec[u].end());
while (vec[u].size() > sq) vec[u].pop_back();
for (auto &[x, y]:vec[u]) y = mn[x];
for (int v:radj[u]) {
left[v]--;
if (!left[v]) q.push(v);
}
}
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
int q;
cin >> n >> m >> q;
for (int i=1;i<=m;i++) {
int u, v;
cin >> u >> v;
radj[u].push_back(v); adj[v].push_back(u);
}
for (int i=1;i<=n;i++) on[i] = true;
ori_ans = solve();
pre();
// for (int i=1;i<=n;i++) {
// for (auto [x, y]:vec[i]) cout << x << "." << y << " "; cout << endl;
// }
while (q--) {
int u, sz;
cin >> u >> sz;
vector<int> off(sz);
for (int &i:off) {
cin >> i;
on[i] = false;
}
if (sz >= sq) {
int ret = solve()[u];
if (!ret && !on[u]) cout << "-1\n";
else cout << ret << "\n";
} else {
// cout << u << endl;
bool flag = true;
for (auto [x, y]:vec[u]) {
// cout << x << " " << y << endl;
if (on[x]) {
cout << ori_ans[u] - y + 1 << "\n";
flag = false;
break;
}
}
if (flag) cout << "-1\n";
}
for (int i:off) on[i] = true;
}
}
