#include <bits/stdc++.h>
#define st first
#define nd second
using lint = int64_t;
constexpr int mod = int(1e9) + 7;
constexpr int inf = 0x3f3f3f3f;
constexpr int ninf = 0xcfcfcfcf;
constexpr lint linf = 0x3f3f3f3f3f3f3f3f;
const long double pi = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
const int SZ = 150;
int n, m, q;
cin>>n>>m>>q;
vector<vector<int>>g(n);
vector<int>d(n);
for(int i=0;i<m;i++){
int a, b;
cin>>a>>b;
a--, b--;
g[a].push_back(b);
d[b]++;
}
vector<vector<pair<int, int>>>prep(n);
for(int i=0;i<n;i++) prep[i] = {{0, i}};
// k-th greatest path to vertice v up to k <= sz + 1
vector<bool>w(n);
{
queue<int>qu;
for(int i=0;i<n;i++) if(!d[i]) qu.push(i);
while(!qu.empty()){
int u = qu.front();
qu.pop();
for(int v : g[u]){
d[v]--;
if(!d[v]) qu.push(v);
int pu = (int)prep[u].size(), pv = (int)prep[v].size();
int s = min(pu + pv, SZ);
vector<pair<int, int>>c(s);
for(int l=0,r=0,i=0;i<s;i++){
while(l < pu && w[prep[u][l].nd]) l++;
while(r < pv && w[prep[v][r].nd]) r++;
if(l < pu && r < pv){
if(prep[u][l].st + 1 >= prep[v][r].st){
c[i] = {prep[u][l].st + 1, prep[u][l].nd}; w[prep[u][l].nd] = 1; l++;
}
else{
c[i] = {prep[v][r].st, prep[v][r].nd}; w[prep[v][r].nd] = 1; r++;
}
}
else if(l < pu){ c[i] = {prep[u][l].st + 1, prep[u][l].nd}; w[prep[u][l].nd] = 1; l++;}
else if(r < pv){ c[i] = {prep[v][r].st, prep[v][r].nd}; w[prep[v][r].nd] = 1; r++;}
else{ c.resize(i); break; }
}
for(auto [dist, id] : c) w[id] = 0;
swap(prep[v], c);
}
}
}
for(int i=0;i<n;i++) w[i] = 0;
for(int T=0;T<q;T++){
int u, k;
cin>>u>>k;
u--;
vector<int>skip(k);
for(int i=0;i<k;i++) cin>>skip[i], skip[i]--;
for(int v : skip) w[v] = 1;
if(k >= SZ){
for(int i=0;i<=u;i++) d[i] = 0;
for(int i=0;i<=u;i++){
for(int v : g[i]){
if(v > u) continue;
d[v]++;
}
}
queue<int>qu;
vector<int>dp(u+1, -1);
for(int i=0;i<=u;i++){
if(!w[i]) dp[i] = 0;
if(!d[i]) qu.push(i);
}
while(!qu.empty()){
int cur = qu.front(); qu.pop();
for(int v : g[cur]){
if(v > u) continue;
if(dp[cur] >= 0) dp[v] = max(dp[v], dp[cur] + 1);
d[v]--;
if(!d[v]) qu.push(v);
}
}
cout<<dp[u]<<"\n";
}
else{
int ans = -1;
for(auto [dist, v] : prep[u]){
if(w[v]) continue;
ans = dist;
break;
}
cout<<ans<<"\n";
}
for(int v : skip) w[v] = 0;
}
return 0;
}
/*
[ ]Leu o problema certo???
[ ]Ver se precisa de long long
[ ]Viu o limite dos fors (é n? é m?)
[ ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[ ]Testar sample
[ ]Testar casos de borda
[ ]1LL no 1LL << i
[ ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/
