// JOI18_bitaro
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;
#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'
#define MAXN 100100
#define SQ 100
int n, m, q;
vector<int> adj[MAXN], badj[MAXN];
int fw[MAXN];
bool busy[MAXN];
bool added[MAXN];
vector<pii> dp[MAXN];
vector<int> advec;
vector<pii> vec;
void merge(vector<pii> dp, vector<pii> &stk)
{
while ((int)vec.size() < SQ)
{
pii p = dp.back();
p.fr++;
if (p > stk.back()) dp.pop_back();
else p = stk.back(), stk.pop_back();
if (added[p.sc]) continue;
if (p.fr < 0) break;
added[p.sc] = true;
advec.pb(p.sc);
vec.pb(p);
}
while ((int)vec.size() < SQ + 1)
vec.pb({-INF, 0});
reverse(all(vec));
stk.swap(vec);
for (int u : advec) added[u] = false;
advec.clear();
vec.clear();
}
int32_t main(void)
{
fast_io;
cin >> n >> m >> q;
FOR(i, 0, m)
{
int x, y;
cin >> x >> y;
adj[x].pb(y);
badj[y].pb(x);
}
vector<pii> stk;
FOR(v, 1, n + 1)
{
FOR(j, 0, SQ) stk.pb({-INF, 0});
stk.pb({0, v});
for (int u : badj[v])
merge(dp[u], stk);
dp[v].swap(stk);
}
vector<int> bs;
while (q--)
{
int t, y;
cin >> t >> y;
FOR(i, 0, y)
{
int x;
cin >> x;
busy[x] = true;
bs.pb(x);
}
if (y >= SQ)
{
int ans = -INF;
fill(fw, fw + n + 10, -INF);
fw[t] = 0;
for (int i = n; i >= 1; i--)
{
for (int u : adj[i])
fw[i] = max(fw[i], fw[u] + 1);
if (!busy[i])
ans = max(ans, fw[i]);
}
if (ans < 0) cout << "-1\n";
else cout << ans << endl;
}
else
{
for (int i = SQ; i >= 0; i--)
if (!busy[dp[t][i].sc])
{
int ans = dp[t][i].fr;
if (ans < 0) cout << "-1\n";
else cout << ans << endl;
break;
}
}
for (int u : bs)
busy[u] = false;
bs.clear();
}
return 0;
}
