#include <bits/stdc++.h>
using namespace std;
#define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I)
#define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I)
#define FOA(I, A) for(auto &I : A)
#define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n';
#define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n';
#define printz(A,L,R) FOR(OK, 1, L){FOR(KO, 1, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n';
#define fs first
#define sd second
#define ii pair<int,int>
#define iii pair<int, ii>
#define all(A) A.begin(), A.end()
#define quickly cin.tie(0) -> ios_base::sync_with_stdio(0);
const int N = 2e5 + 5;
const int SQRT = 320;
const int oo = 1e9;
int n, m, q;
bool dead[N], vis[N];
int f[N], cnt[N];
vector<int> g[N];
signed main(){ quickly
cin >> n >> m >> q;
FOR(i, 1, m){
int u, v;
cin >> u >> v;
g[v].push_back(u);
}
while(q--){
int t, s;
cin >> t >> s;
bool is = 0;
memset(dead, 0, sizeof dead);
memset(f, 0, sizeof f);
FOR(i, 1, s){
int u; cin >> u;
dead[u] = 1;
if(u == t) is = 1;
}
FOR(u, 1, t){
FOA(v, g[u]){
if(!dead[v]){
f[u] = max(f[v] + 1, f[u]);
}
else{
if(f[v] != 0){
f[u] = max(f[u], f[v] + 1);
}
}
}
}
if(f[t] == 0 && is == 1){
cout << -1 << '\n';
continue;
}
cout << f[t] << '\n';
}
}
