#include<bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define sz(x) ( (int)(x).size() )
using LL = long long;
template<class T>
inline bool asMn(T &a, const T &b) { return a > b ? a = b, true : false; }
template<class T>
inline bool asMx(T &a, const T &b) { return a < b ? a = b, true : false; }
const int bdr = 400;
mt19937 rng( (uint32_t)chrono::steady_clock::now().time_since_epoch().count() );
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef FourLeafClover
freopen("input", "r", stdin);
#endif // FourLeafCLover
int n, m, q; cin >> n >> m >> q;
vector<vector<int> > gr(n);
while (m--) {
int s, e; cin >> s >> e; --s; --e;
gr[e].emplace_back(s);
}
vector<vector<pair<int, int> > > d(n);
vector<int> val(n, -1), wait;
for (int u = 0; u < n; ++u) {
for (int v : gr[u]) {
for (auto _ : d[v]) {
if (val[_.second] == -1) wait.emplace_back(_.second);
asMx(val[_.second], _.first + 1);
}
}
asMx(val[u], 0);
wait.emplace_back(u);
nth_element(wait.begin(), wait.begin() + min(bdr, sz(wait) ), wait.end(), [&](int i, int j) { return val[i] > val[j]; });
for (int i = 0; i < min(bdr, sz(wait) ); ++i) d[u].emplace_back(pair<int, int>{ val[ wait[i] ], wait[i] } );
for (int v : wait) val[v] = -1;
wait.clear();
}
vector<int> f(n, -1);
vector<bool> banned(n, false);
function<int(int)> F = [&](int u) {
if (~f[u]) return f[u];
f[u] = (banned[u] ? -2 : 0);
for (int v : gr[u]) if (F(v) >= 0) asMx(f[u], f[v] + 1);
return f[u];
};
while (q--) {
int t, y; cin >> t >> y; --t;
vector<int> tmp(y);
for (auto &u : tmp) {
cin >> u; --u;
banned[u] = true;
}
if (y >= bdr) {
cout << max(F(t), -1) << '\n';
f.assign(n, -1);
}
else {
int ans = -1;
for (auto _ : d[t]) if (!banned[_.second]) asMx(ans, _.first);
cout << ans << '\n';
}
for (int u : tmp) banned[u] = false;
}
return 0;
}
