#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize ("Ofast,unroll-loops")
// #pragma GCC target ("avx,avx2,fma")
using namespace std;
using namespace __gnu_pbds;
typedef int ll;
typedef long double ld;
typedef pair <ll, ll> pll;
#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1);
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< x << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()
cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;
template <class A, class B> ostream& operator << (ostream& out, const pair<A, B> &a) {
return out << '(' << a.first << ", " << a.second << ')'; }
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
if(!a.size())return cout<<"[]";cout<< '[' << a[0]; for (int i = 0; ++i < (int)(a.size());) cout<< ", " << a[i];cout<< ']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;
cl N = 1e5 + 7, SQ = 300;
ll pos [N], dis [N], n, m, q, ans;
vector <ll> adj [N], jda [N], tops, vec;
vector <pll> dp [N], tmp;
bool mark [N];
void dfs (ll v) {
mark[v] = 1;
for (auto u : adj[v]) if (!mark[u]) dfs(u);
pos[v] = n - SZ(tops) - 1, tops.push_back(v);
}
void _merge (vector <pll> &v, vector <pll> &u) {
vector <pll> res;
ll l1 = 0, l2 = 0;
while (l1 < SZ(v) && l2 < SZ(u) && l1 + l2 <= SQ) {
if (v[l1] == pll(u[l2].fr + 1, u[l2].sc)) res.push_back(v[l1++]), l2++;
else if (v[l1].fr > u[l2].fr + 1) res.push_back(v[l1++]);
else res.push_back({u[l2].fr + 1, u[l2].sc}), l2++;
}
while (l1 < SZ(v) && l1 + l2 <= SQ) res.push_back(v[l1++]);
while (l1 < SZ(v) && l1 + l2 <= SQ) res.push_back({u[l2].fr + 1, u[l2].sc}), l2++;
v.swap(res);
}
int main ()
{
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
memset(dis, -61, sizeof dis); cin>> n >> m >> q;
for (ll i = 0, v, u; i < m; i++) cin>> v >> u, adj[v].push_back(u), jda[u].push_back(v);
for (ll i = 1; i <= n; i++) if (!mark[i]) dfs(i);
reverse(All(tops)); memset(mark, 0, sizeof mark);
for (auto v : tops) {
dp[v].push_back({0, v});
for (auto u : jda[v]) _merge(dp[v], dp[u]);
}
for (ll v, t, i; q--;) {
cin>> v >> t;
vec.resize(t); for (auto &x : vec) cin>> x, mark[x] = 1;
if (t < SQ) {
for (i = 0; i < SZ(dp[v]) && mark[dp[v][i].sc]; i++);
cout<< (i < SZ(dp[v]) ? dp[v][i].fr : -1) << '\n';
} else {
for (ans = 0, dis[v] = 0, i = pos[v] - 1; ~i; i--) {
for (auto u : adj[tops[i]]) dis[tops[i]] = max(dis[tops[i]], dis[u] + 1);
if (!mark[tops[i]]) ans = max(ans, dis[tops[i]]);
}
cout<< ans << '\n';
for (i = 0; i <= pos[v]; i++) dis[tops[i]] = -inf;
}
for (auto &x : vec) mark[x] = 0;
}
return 0;
}
/*
*/
