#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define sp << " " <<
//#define int long long
#define vi vector<int>
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define wtf {cout << "OK\n"; return;}
const int N = 1e5+1,MOD = 998244353,B = 350,inf = 2e9;
vi used(N,0);
void merge(vector<pii>& v1, vector<pii>& v2) {
int n = v1.size();
int m = v2.size();
int p1 = 0;
int p2 = 0;
vi toggle;
vector<pii> ans;
while (p1<n && p2 < m) {
if (v1[p1].first > v2[p2].first) {
if (used[v1[p1].second]) ;
else {
used[v1[p1].second] = 1;
toggle.push_back(v1[p1].second);
ans.push_back(v1[p1]);
}
p1++;
}
else {
if (used[v2[p2].second]) ;
else {
used[v2[p2].second] = 1;
toggle.push_back(v2[p2].second);
ans.push_back(v2[p2]);
}
p2++;
}
}
while (p1 < n) {
if (used[v1[p1].second]);
else {
used[v1[p1].second] = 1;
toggle.push_back(v1[p1].second);
ans.push_back(v1[p1]);
}
p1++;
}
while (p2 < m) {
if (used[v2[p2].second]);
else {
used[v2[p2].second] = 1;
toggle.push_back(v2[p2].second);
ans.push_back(v2[p2]);
}
p2++;
}
if (ans.size() > B) ans.resize(B);
v1 = ans;
for (auto it : toggle) used[it] = 0;
}
void solve() {
int n,m,q;
cin >> n >> m >> q;
vi edges[n+1],egdes[n+1],inc(n+1,0),vis(n+1,0);
for (int i=1;i<=m;i++) {
int a,b;
cin >> a >> b;
edges[a].push_back(b);
egdes[b].push_back(a);
inc[b]++;
}
vector<pii> gnomes[n+1];
vector<pii> gotgnomes[n+1];
queue<int> qq;
vi order;
for (int i=1;i<=n;i++) if (!inc[i]) qq.push(i);
while (!qq.empty()) {
int f = qq.front();
order.push_back(f);
gnomes[f].push_back({0,f});
qq.pop();
for (auto it : egdes[f]) {
for (auto& itt : gnomes[it]) ++itt.first;
merge(gnomes[f],gnomes[it]);
for (auto& itt : gnomes[it]) --itt.first;
}
for (auto it : edges[f]) {
if (!vis[it]) {
inc[it]--;
if (!inc[it]){
vis[it] = 1;
qq.push(it);
}
}
}
}
vector<vector<pii>> gnomevector(n+1);
for (int i=1;i<=n;i++) for (auto it : gnomes[i]) gnomevector[i].push_back(it);
vi banned(n+1,0);
while (q--) {
int party,ban;
cin >> party >> ban;
vi bans(ban);
for (int i=1;i<=ban;i++) {
cin >> bans[i-1];
banned[bans[i-1]] = 1;
}
if (ban < B) {
//Just check possible ones
bool broken = 0;
for (auto it : gnomevector[party]) {
if (!banned[it.second]) {
cout << it.first << '\n';
broken = 1;
break;
}
}
if (!broken) cout << -1 << '\n';
}
else {
//Do it again only sqrt(Y) can be like this
vi dp(n+1,-inf);
for (auto it : order) {
if (!banned[it]) dp[it] = 0;
for (auto itt : egdes[it]) dp[it] = max(dp[it],dp[itt]+1);
}
cout << (dp[party]<0?-1:dp[party]) << '\n';
}
for (int i=1;i<=ban;i++) banned[bans[i-1]] = 0;
}
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Local
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
