#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"
using namespace std;
using namespace __gnu_pbds;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T, typename key = less_equal<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
const ll B = 320, N = 1e5 + 5;
vector<ll> g[N], gr[N];
vector<pair<ll, ll>> best[N];
bool used[N], us[N];
ll dp[N];
vector<ll> top;
void dfs(ll v)
{
used[v] = 1;
vector<pair<ll, ll>> tmp;
best[v].push_back(make_pair(0, v));
for (ll to : gr[v])
{
if (!used[to]) dfs(to);
tmp.clear();
ll i = 0, j = 0;
while (tmp.size() < B + 1)
{
while (i < best[v].size() and us[best[v][i].second]) i++;
while (j < best[to].size() and us[best[to][j].second]) j++;
if (i == best[v].size() and j == best[to].size()) break;
if (i == best[v].size())
tmp.push_back(make_pair(best[to][j].first + 1, best[to][j].second)), j++;
else if (j == best[to].size())
tmp.push_back(best[v][i]), i++;
else if (best[v][i].first < best[to][j].first + 1) tmp.push_back(make_pair(best[to][j].first + 1, best[to][j].second)), j++;
else tmp.push_back(best[v][i]), i++;
us[tmp.back().second] = 1;
}
best[v] = tmp;
for (auto i : best[v]) us[i.second] = 0;
}
}
void solve()
{
ll n, m, q;
cin >> n >> m >> q;
while (m--)
{
ll a, b;
cin >> a >> b;
g[a].push_back(b);
gr[b].push_back(a);
}
for (ll i = 1; i <= n; i++) if (!used[i]) dfs(i);
while (q--)
{
ll t, k;
cin >> t >> k;
ll x[k];
for (ll i = 0; i < k; i++)
cin >> x[i], us[x[i]] = 1;
ll ans = -1;
if (k <= B)
{
for (auto i : best[t])
if (!us[i.second])
{
ans = i.first;
break;
}
}
else
{
for (ll i = 1; i <= n; i++) dp[i] = -1e9;
dp[t] = 0;
for (ll i = t; i >= 1; i--)
{
for (ll j : g[i]) dp[i] = max(dp[i], dp[j] + 1);
if (!us[i]) ans = max(ans, dp[i]);
}
}
for (ll i = 0; i < k; i++) us[x[i]] = 0;
cout << ans << endl;
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
ll t = 1;
// precomp();
// cin >> t;
for (ll cs = 1; cs <= t; cs++)
solve();
// cerr << "\nTime elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}
