#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 100005;
const ll MOD = 1000000007;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int SQ = 300;
vector<int> to[N], fr[N];
vector<pair<int, int> > ans[N];
int vis[N];
int tag = 0;
int d[N];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m, q;
cin>>n>>m>>q;
while(m--){
int s, e;
cin>>s>>e;
fr[s].push_back(e);
to[e].push_back(s);
}
for(int i = 1; i <= n; ++i){
ans[i].push_back({i, 0});
for(auto& j : to[i]){
++tag;
vector<pair<int, int> > tmp, &v1 = ans[i], &v2 = ans[j];
int i1 = 0, i2 = 0, s1 = v1.size(), s2 = v2.size();
while(tmp.size() < SQ && (i1 < s1 || i2 < s2) ){
if(i1 != s1 && vis[v1[i1].ff] == tag){
++i1;
continue;
}
if(i2 != s2 && vis[v2[i2].ff] == tag){
++i2;
continue;
}
if(i2 == s2 || v1[i1].ss > v2[i2].ss + 1){
vis[v1[i1].ff] = tag;
tmp.push_back({v1[i1].ff, v1[i1].ss});
++i1;
continue;
}
vis[v2[i2].ff] = tag;
tmp.push_back({v2[i2].ff, v2[i2].ss + 1});
++i2;
}
swap(v1, tmp);
}
}
while(q--){
++tag;
int res = -1;
int t, y;
cin>>t>>y;
while(y--){
int w;
cin>>w;
vis[w] = tag;
}
for(auto& [v, d] : ans[t]){
if(vis[v] != tag){
res = d;
break;
}
}
if(res != -1){
cout<<res<<'\n';
continue;
}
for(int i = t + 1; i <= n; ++i)
d[i] = -MOD;
d[t] = 0;
if(vis[t] != tag)
res = 0;
for(int i = t - 1; i > 0; --i){
d[i] = -MOD;
for(auto& x : fr[i])
d[i] = max(d[i], d[x] + 1);
if(vis[i] != tag)
res = max(res, d[i]);
}
cout<<res<<'\n';
}
}
