//start-time: 2024-04-14 19:39:32
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll w = round(sqrt(100000)) + 1;
void solve(){
ll n, m, q;
cin >> n >> m >> q;
vector<vector<ll>> g(n);
vector<vector<ll>> gR(n);
for(ll i = 0; i < m; i++){
ll u, v;
cin >> u >> v;
u--; v--;
g[u].push_back(v);
gR[v].push_back(u);
}
vector<ll> vis(n), topo;
auto dfs = [&](ll u, auto&&dfs) -> void {
vis[u] = 1;
for(auto v : g[u]){
if(!vis[v]){
dfs(v, dfs);
}
}
vis[u] = 2;
topo.push_back(u);
};
for(int i = 0; i < n; i++){
if(vis[i] == 0){
dfs(i, dfs);
}
}
reverse(topo.begin(), topo.end());
vector<vector<array<ll, 2>>> dp(n);
for(auto u : topo){
vector<ll> val(n, -1), aux;
aux.push_back(u);
val[u] = 0;
for(auto v : gR[u]){
for(auto [value, ind] : dp[v]){
aux.push_back(ind);
val[ind] = max(val[ind], value + 1);
}
}
sort(aux.begin(), aux.end());
aux.erase(unique(aux.begin(), aux.end()), aux.end());
sort(aux.begin(), aux.end(), [&](int a, int b){
return val[a] > val[b];
});
for(auto el : aux){
if(dp[u].size() < w){
dp[u].push_back({val[el], el});
}
}
}
for(ll i = 0; i < q; i++){
ll u, y;
cin >> u >> y;
u--;
vector<bool> c(100'001);
for(ll j = 0; j < y; j++){
ll a; cin >> a;
c[--a] = 1;
}
ll ans = -1;
if(y < w) {
for(auto [v, i] : dp[u]){
if(!c[i]){
ans = max(ans, v);
}
}
}
else {
vector<int> naive(n);
for(auto v : topo){
naive[v] = c[v] ? -1 : 0;
for(auto el : gR[v]){
naive[v] = max(naive[v], naive[el] + (naive[el] != -1));
}
}
ans = naive[u];
}
//for(auto el : naive){
//cout << el << ' ';
//}
//cout << endl;
cout << ans << endl;
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
ll T = 1;
//cin >> T;
while(T--) solve();
return 0;
}
