#include <bits/stdc++.h>
using namespace std;
#define MAXN 450
#define pii array<int,2>
bool cmp(const pii &x, const pii &y) {
if (x[1] != y[1]) return x[1] > y[1];
return x[0] > y[0];
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n,m,q;cin>>n>>m>>q;
vector<vector<int>> g(n);
for (int i=0;i<m;i++) {
int a,b;cin>>a>>b;a--;b--;
g[a].push_back(b);
}
// precalc
vector<vector<pii>> pref(n);
for (int i=0;i<n;i++) {
pref[i].push_back({i, 0});
}
vector<vector<int>> bucket(n+2);
vector<bool> seen(n+2, false);
for (int i=0;i<n;i++) {
// bucket sort
// sort(pref[i].begin(), pref[i].end(), cmp);
int mx = 0;
for (auto &x:pref[i]) {
mx = max(mx, x[1]);
bucket[x[1]].push_back(x[0]);
}
vector<pii> tmp;
int cnt=0;
for (int j=mx;j>=0;j--) {
for (auto x:bucket[j]) {
if (!seen[x]) {
seen[x] = true;
tmp.push_back({x, j});
cnt++;
if (cnt == MAXN) break;
}
}
if (cnt == MAXN) break;
}
// cout<<tmp.size()<<"\n";
for (auto &x:pref[i]) {
bucket[x[1]].clear();
seen[x[1]]=false;
}
pref[i].clear();
pref[i] = tmp;
// vector<pii> tmp;
// int cnt=0;
// for (auto x:pref[i]) {
// if (!seen[x[0]]) {
// tmp.push_back(x);
// seen[x[0]]=true;
// cnt++;
// if (cnt == MAXN) break;
// }
// }
// pref[i] = tmp;
for (auto x:tmp) {
seen[x[0]]=false;
}
for (int x:g[i]) {
for (auto y:pref[i]) {
pref[x].push_back({y[0], y[1]+1});
}
}
}
// for (int i=0;i<n;i++) {
// cout<<i+1<<"\n";
// for (auto x:pref[i]) {
// cout<<"node: "<<x[0]+1<<", length: "<<x[1]<<"\n";
// }
// cout<<"\n";
// }
for (int i=0;i<q;i++) {
int t,y;cin>>t>>y;
vector<int> val(y);
for (auto &x:val){cin>>x;x--;seen[x]=true;}
t--;
bool found = false;
for (auto x:pref[t]) {
if (!seen[x[0]]) {
cout<<x[1]<<"\n";
found = true;
break;
}
}
if (!found && pref[t].size() >= MAXN) {
vector<int> dp(n, 0);
for (int i=0;i<n;i++) {
if (seen[i]) continue;
for (int x:g[i]) {
dp[x] = max(dp[x], dp[i]+1);
}
}
if (dp[t] != 0 || !seen[t]) {
cout<<dp[t]<<"\n";
}
else {
cout<<"-1\n";
}
}
else if (!found) {
cout<<-1<<"\n";
}
for (auto x:val) {
seen[x] = false;
}
}
}
