#include <bits/extc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using namespace __gnu_pbds;
#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<vector<pair<ll,ll>>> pq;
void solve()
{
cin >> N >> M >> Q;
adj.resize(N);
pq.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 = 200;
//precompute
vector<ll> vis(N, -1);
vector<ll> sz(N, 0);
for(ll i = 0; i < N; i++)
{
pq[i].emplace_back(0, i);
sz[i]++;
sort(all(pq[i]), greater<pair<ll,ll>>());
ll ij = 0; // last free
for(ll k = 0; k < sz[i] && k <= SQRT; k++)
{
if(vis[pq[i][k].second] != i)
{
vis[pq[i][k].second] = i;
pq[i][ij] = pq[i][k];
ij++;
}
}
sz[i] = ij;
// cout << "prc: " << i << " " << sz[i] << " " << pq[i].size() << "\n";
for(auto e : adj[i])
{
for(ll k = 0; k < sz[i]; k++)
{
auto [d,v] = pq[i][k];
pq[e].emplace_back(d+1, v);
sz[e]++;
}
}
}
int ij = 0;
vector<ll> del(N, -1);
while(Q--)
{
ll T, Y;
cin >> T >> Y;
--T;
ll x;
for(ll i = 0; i < Y; i++)
{
cin >> x;
del[--x] = ij;
}
vector<ll> dp(N, -1);
if(Y >= SQRT)
{
fill(all(dp), -1);
for(ll i = 0; i <= T; i++)
{
if(del[i] != ij) 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
{
// continue;
bool b = 0;
for(auto e : pq[T])
{
// cout << e.first << " " << e.second << " " << del[e.second] << " " << ij << "\n";
if(del[e.second] == ij) continue;
else
{
cout << e.first << "\n";
b = 1;
break;
// break;
}
}
if(!b)
cout << "-1\n";
}
ij++;
}
}
