#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 = 1500;
ll dis [N], n, m, q;
vector <ll> adj [N], jda [N], vec;
vector <pll> dp [N];
int main ()
{
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin>> n >> m >> q;
for (ll i = 0, v, u; i < m; i++) cin>> v >> u, adj[u].push_back(v), jda[v].push_back(u);
for (ll i = 1; i <= n; i++) {
dp[i] = {{0, i}};
for (auto u : adj[i]) {
dp[0] = dp[u];
for (auto &x : dp[0]) x.fr++;
dp[n+1].clear();
merge(All(dp[i]), All(dp[0]), back_inserter(dp[n+1]), greater<pll>());
dp[n+1].resize(unique(All(dp[n+1])) - dp[n+1].begin()); dp[n+1].resize(min(SQ, SZ(dp[n+1])));
dp[i].swap(dp[n+1]);
}
}
for (ll v, t, i; q--;) {
cin>> v >> t;
vec.resize(t); for (auto &x : vec) cin>> x, dis[x] = -1;
if (t < SQ) {
for (i = 0; i < SZ(dp[v]) && dis[dp[v][i].sc] == -1; i++);
cout<< (i < SZ(dp[v]) ? dp[v][i].fr : -1) << '\n';
for (auto &x : vec) dis[x] = 0;
} else {
memset(dis, 0, sizeof dis);
for (auto u : vec) dis[u] = -1;
for (i = 1; i <= v; i++) if (~dis[i]) for (auto u : adj[i]) {
dis[u] = max(dis[u], dis[i] + 1);
}
cout<< dis[v] << '\n';
}
}
return 0;
}
/*
*/
