#include "bits/stdc++.h"
using namespace std;
#define ar array
const int N = 2e5 + 5;
const int B = 350;
int n, m, q;
vector<int> edges[N];
vector<ar<int, 2>> par[N];
void build(){
vector<int> used(n + 1), cost(n + 1);
for(int i=1;i<=n;i++){
vector<int> rr;
cost[i] = 0, rr.push_back(i);
for(auto x : edges[i]){
for(auto v : par[x]){
if(used[v[1]] == i){
cost[v[1]] = max(cost[v[1]], v[0] + 1);
} else {
rr.push_back(v[1]);
used[v[1]] = i;
cost[v[1]] = v[0] + 1;
}
}
}
sort(rr.begin(), rr.end(), [&](int a, int b){
return cost[a] > cost[b];
});
rr.resize(min((int)rr.size(), B));
for(auto x : rr) par[i].push_back({cost[x], x});
}
}
signed main(){
ios::sync_with_stdio(0); cin.tie(0);
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int a, b; cin>>a>>b;
edges[b].push_back(a);
}
build();
vector<int> used(n + 1);
while(q--){
int u; cin>>u;
int sz, res = -1; cin>>sz;
vector<int> a(sz);
for(auto& x : a) cin>>x, used[x] = 1;
if(sz >= B){
vector<int> dis(n + 1, -1);
for(int i=1;i<=n;i++){
if(!used[i]) dis[i] = 0;
for(auto x : edges[i]){
if(~dis[x]) dis[i] = max(dis[i], dis[x] + 1);
}
} res = dis[u];
} else {
for(auto x : par[u]){
if(used[x[1]]) continue;
res = x[0];
break;
}
}
cout<<res<<"\n";
for(auto x : a) used[x] = 0;
}
}
