#pragma GCC optimize("O3")
#pragma GCC optimization("Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzd,popd")
#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define ll long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
#define FOD(i, r, l) for (int i = (r); i >= (l); i--)
#define fi first
#define se second
#define pii pair<int, int>
const ll mod = 998244353;
const int MAXN = 200000 + 5;
const ll oo = 1e9;
const ll base = 350;
int n, m, q;
vector<int> adj[MAXN], adj1[MAXN];
vector<pii> vec[MAXN];
vector<pii> merge(vector<pii> &a, vector<pii> &b){
vector<pii> v;
int j=0;
FOR(i, 0, (int)a.size()-1){
while(j<=(int)b.size()-1 && b[j].fi+1<=a[i].fi){
v.push_back({b[j].fi+1, b[j].se});
j++;
}
v.push_back(a[i]);
}
FOR(jj, j, (int)b.size()-1){
v.push_back({b[jj].fi+1, b[jj].se});
}
vector<pii> vv;
FOR(i, 0, (int)v.size()-1){
if(i==(int)v.size()-1 || v[i].se!=v[i+1].se){
vv.push_back(v[i]);
}
}
vector<pii> vvv;
FOR(i, max(0LL, (int)vv.size()-1-base+1), (int)vv.size()-1){
vvv.push_back(vv[i]);
}
return vvv;
}
void preproces(){
FOR(u, 1, n){
vec[u].push_back({0, u});
for(auto v:adj1[u]){
// cout << u << ' ' << v << '\n';
vec[u]=merge(vec[u], vec[v]);
}
}
}
int c[MAXN], chk[MAXN];
int f[MAXN];
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
if (fopen(".inp", "r")){
freopen(".inp", "r", stdin);
freopen(".out", "w", stdout);
}
cin >> n >> m >> q;
FOR(i, 1, m){
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj1[v].push_back(u);
}
preproces();
// FOR(i, 1, n){
// cout << i << '\n';
// for(auto [v, w]:vec[i]){
// cout << v << ' ' << w << " ";
// }
// cout << '\n';
// }
FOR(i, 1, q){
int t, y;
cin >> t >> y;
FOR(j, 1, y){
cin >> c[j];
chk[c[j]]=1;
}
if(y<=base-5){
int chek=0;
FOD(j, (int)vec[t].size()-1, 0){
auto [w, v]=vec[t][j];
if(!chk[v]){
chek=1;
cout << w;
break;
}
}
if(!chek){
cout << -1;
}
}
else{
FOR(u, 1, n){
if(chk[u]){
f[u]=-oo;
}
else{
f[u]=0;
}
for(auto v:adj1[u]){
f[u]=max(f[u], f[v]+1);
}
}
if(f[t]<=-1e8){
f[t]=-1;
}
cout << f[t];
}
FOR(j, 1, y){
chk[c[j]]=0;
}
cout << '\n';
}
return 0;
}
