#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#define ll long long
#define pb push_back
#define m_pi 2 * acos(0.0)
#define all(a) (a).begin(), (a).end()
#define LL_INF 0x3f3f3f3f3f3f3f3f
#define INF 0x3f3f3f3f
void solve();
constexpr bool isTc = 0;
int main()
{
// ios_base::sync_with_stdio(0);
// cin.tie(0);
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
if (isTc)
{
int T;
cin >> T;
while (T--)
{
solve();
}
}
else
solve();
return 0;
}
/*######################################*/
ll N, M, Q;
vector<vector<ll>> adj;
vector<set<pair<ll,ll>, greater<pair<ll,ll>>>> pq;
vector<unordered_map<ll,ll>> mp;
void solve()
{
cin >> N >> M >> Q;
adj.resize(N);
pq.resize(N);
mp.resize(N);
for(ll i = 0; i < M; i++)
{
ll a,b;
cin >> a >> b, --a, --b;
adj[a].emplace_back(b);
}
constexpr ll SQRT = 315;
//precompute
for(ll i = 0; i < N; i++)
{
pq[i].insert({0, i});
mp[i][i] = 0;
for(auto ed : adj[i])
{
for(auto [d, e] : pq[i])
{
if(mp[ed].find(e) != mp[ed].end())
{
if(mp[ed][e] < d+1)
{
pq[ed].erase({mp[ed][e], e});
pq[ed].insert({d+1, e});
mp[ed][e] = d+1;
}
continue;
}
if(pq[ed].size() >= SQRT)
{
if((*pq[ed].rbegin()).first < d+1)
{
mp[ed].erase((*pq[ed].rbegin()).second);
pq[ed].erase(*pq[ed].rbegin());
}
else continue;
}
pq[ed].insert({d+1, e});
mp[ed][e] = d+1;
}
}
}
while(Q--)
{
ll T, Y;
cin >> T >> Y;
--T;
unordered_set<ll> P;
ll x;
for(ll i = 0; i < Y; i++)
{
cin >> x;
P.insert(--x);
}
if(Y >= SQRT)
{
vector<ll> dp(N, -1);
for(ll i = 0; i <= T; i++)
{
if(!P.count(i)) dp[i] = max(dp[i], 0ll);
if(dp[i] != -1)
{
for(auto e : adj[i])
{
dp[e] = max(dp[e], dp[i]+1);
}
}
}
cout << dp[T] << "\n";
}
else
{
bool b = 0;
for(auto e : pq[T])
{
// cout << e.first << " " << e.second << "\n";
if(P.count(e.second)) continue;
else
{
cout << e.first << "\n";
b = 1;
break;
// break;
}
}
if(!b)
cout << "-1\n";
}
}
}
