#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 100010;
const int B = 315;
int n, m, q, d[N], b[N];
bool vis[N], busy[N];
vector<int> adj[N], rev[N];
vector<pair<int, int>> f[N];
void precompute() {
for (int i = 1; i <= n; ++i) {
vector<pair<int, int>> tmp;
for (auto v: rev[i]) {
for (auto x: f[v]) {
tmp.push_back({x.first+1, x.second});
}
}
tmp.push_back({0, i});
sort(tmp.begin(), tmp.end(), greater<pair<int, int>>());
for (auto x: tmp) {
if (!vis[x.second]) {
vis[x.second] = true;
f[i].push_back(x);
if (f[i].size() == B) break;
}
}
for (auto p: f[i]) vis[p.second] = false;
}
}
int solve(int source) {
int ans = -1;
for (auto x: f[source]) {
if (!busy[x.second]) {
ans = max(ans, x.first);
}
}
return ans;
}
int brute(int source) {
for (int i = 1; i <= n; ++i) d[i] = INT_MIN;
d[source] = 0;
for (int i = source-1; i >= 1; --i) {
for (auto v: adj[i]) {
d[i] = max(d[i], d[v] + 1);
}
}
int ans = -1;
for (int i = 1; i <= source; ++i) {
if (!busy[i]) ans = max(ans, d[i]);
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> q;
for (int i = 1; i <= m; ++i) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
rev[v].push_back(u);
}
precompute();
while (q--) {
int node, sz;
cin >> node >> sz;
for (int i = 1; i <= sz; ++i) {
cin >> b[i];
busy[b[i]] = true;
}
if (sz >= B) {
cout << brute(node) << '\n';
} else {
cout << solve(node) << '\n';
}
for (int i = 1; i <= sz; ++i) {
busy[b[i]] = false;
}
}
}
