// Born_To_Laugh - Hughie Do
#include <bits/stdc++.h>
#define alle(AC) AC.begin(), AC.end()
#define fi first
#define se second
using namespace std;
typedef long long ll;
[[maybe_unused]] const ll MOD = 998244353, INF = 1e9 + 7;
#define int ll
const int maxn = 1e5 + 10;
const int sq = 320;
int n, m, q, vis[maxn], added[maxn], rem[maxn];
vector<int> adj[maxn], radj[maxn];
vector<pair<int, int>> li[maxn];
vector<int> topo;
void dfs(int a){
vis[a] = 1;
for(auto &elm: adj[a]) if(!vis[elm]) dfs(elm);
topo.push_back(a);
}
void buildli(){
for(auto &a: topo){
priority_queue<pair<pair<int,int>,pair<int,int>>> pq;
for(auto &elm: radj[a]){
pq.push({li[elm][0], {elm, 0}});
}
for(int i=1; i<=320 && !pq.empty(); ++i){
auto x = pq.top();
pq.pop();
if(!added[x.fi.se]){
li[a].push_back({x.fi.fi + 1, x.fi.se});
added[x.fi.se] = 1;
}
if(li[x.se.fi].size() > x.se.se + 1){
pq.push({li[x.se.fi][x.se.se + 1], {x.se.fi, x.se.se + 1}});
}
}
if(li[a].size() < 320) li[a].push_back({0, a});
for(auto &elm: li[a]) added[elm.se] = 0;
}
}
int ope1(int x, int y, vector<int> &sth){
for(auto &elm: sth) rem[elm] = 1;
int ans = -1;
for(auto &elm: li[x]){
if(rem[elm.se]) continue;
ans = elm.fi;
break;
}
for(auto &elm: sth) rem[elm] = 0;
return ans;
}
int ope2(int x, int y, vector<int> &sth){
for(auto &elm: sth) rem[elm] = 1;
vector<int> dp(n + 1, -INF);
dp[x] = 0;
int ans = -1;
for(int i = n - 1; i>=0; --i){
int a = topo[i];
for(auto &elm: adj[a]){
if(dp[elm] != INF) dp[a] = max(dp[a], dp[elm] + 1);
}
if(!rem[a] && dp[a] != INF) ans = max(ans, dp[a]);
}
for(auto &elm: sth) rem[elm] = 0;
return ans;
}
void solve(){
cin >> n >> m >> q;
for(int i=1; i<=m; ++i){
int a, b;cin >> a >> b;
adj[a].push_back(b);
radj[b].push_back(a);
}
for(int i=1; i<=n; ++i) if(!vis[i]) dfs(i);
reverse(alle(topo));
buildli();
while(q--){
int x, y;cin >> x >> y;
vector<int> sth(y);
for(int i=0; i<y; ++i) cin >> sth[i];
// cout << ope2(x, y, sth) << '\n';
if(y < 320){
cout << ope1(x, y, sth) << '\n';
}
else{
cout << ope2(x, y, sth) << '\n';
}
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
