#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<int, int> pii;
typedef pair<ld, ld> pld;
int n, m, q;
int sq = 250;
vector<int> inc[200009];
vector<pii> far[200009];
int dist[200009];
int nono[200009];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
cin >> n >> m >> q;
while(m--){
int x, y;
cin >> x >> y;
inc[y].pb(x);
}
for(int i = 1; i <= n; ++i)
dist[i] = -1;
for(int i = 1; i <= n; ++i){
far[i].pb({0, i});
for(auto u1 : inc[i])
for(auto u2 : far[u1])
dist[u2.ss] = max(dist[u2.ss], u2.ff+1);
for(auto u1 : inc[i])
for(auto u2 : far[u1])
if(dist[u2.ss] != -1){
far[i].pb({dist[u2.ss], u2.ss});
dist[u2.ss] = -1;
}
sort(far[i].begin(), far[i].end(), greater<pll>());
while((int)far[i].size() > sq)
far[i].pop_back();
}
while(q--){
int root, k;
cin >> root >> k;
vector<int> busy(k);
for(int i = 0; i < k; ++i){
cin >> busy[i];
nono[busy[i]] = 1;
}
if(k < sq){
int neg = 1;
for(auto u : far[root])
if(nono[u.ss] == 0){
neg = 0;
cout << u.ff << "\n";
break;
}
if(neg)
cout << "-1\n";
}
else{
for(int i = 1; i < root; ++i)
dist[i] = -1;
dist[root] = 0;
int ans = -1;
for(int i = root; i >= 1; --i){
if(dist[i] == -1)
continue;
if(dist[i] > ans && nono[i] == 0)
ans = dist[i];
for(auto u : inc[i])
dist[u] = max(dist[u], dist[i]+1);
}
cout << ans << "\n";
}
for(int i = 0; i < k; ++i){
nono[busy[i]] = 0;
}
}
}
