#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 1e5;
const int sq = 336;
vector<int> adj[maxn],in[maxn];
set<pair<int,int>> st[maxn];
int u,v,q,n,m,y,c,h,currt[maxn],res;
void inp(){
cin >> n >> m >> q;
for (int i = 1 ; i <= m; i++){
cin >> u >> v;
adj[u].push_back(v);
in[v].push_back(u);
}
fill(currt, currt+n+1, -1);
}
void prep(){
for (int i = 1 ; i <= n ; i++){
st[i].insert({0, i});
}
for (int i = 1 ; i <= n ; i++){
set<pair<int,int>> bag;
for (auto it : in[i]){
for (auto el : st[it]){
bag.insert(el);
}
}
vector<bool> is(n+1, false);
while ((int)bag.size() && (int)st[i].size() < sq){
pair<int,int> p = *bag.rbegin();
bag.erase(*bag.rbegin());
if (is[p.second]) continue;
is[p.second] = true;
st[i].insert({p.first + 1, p.second});
}
}
}
void query(){
while (q--){
cin >> h >> y;
for (int i = 1 ; i <= y ; i++){
cin >> c;
currt[c] = q;
}
if (q != 1 && y < sq){
res = -1;
for (auto it : st[h]){
if (currt[it.second] != q){
res = max(res, it.first);
}
}
if (currt[h] != q) res = max(res, 0);
}
else{ // dp
vector<int> dp(n+1, -1);
res = -1;
dp[h] = 0;
for (int i = n ; i >= 1 ; i--){
for (auto it : adj[i]){
if (dp[it] == -1) continue;
dp[i] = max(dp[it] + 1, dp[i]);
}
if (currt[i] != q) res = max(res, dp[i]);
}
}
cout << res << '\n';
}
}
int main(){
ios_base::sync_with_stdio(false);
inp();
prep();
query();
}
