#include <bits/stdc++.h>
using namespace std;
#define MOD1 1000000007
#define MOD2 998244353
#define fir first
#define sec second
#define pushf push_front
#define pushb push_back
#define popf pop_front
#define popb pop_back
#define mp make_pair
#define all(a) a.begin(), a.end()
#define lbound(v, x) lower_bound(all(v), x) - v.begin()
#define ubound(v, x) upper_bound(all(v), x) - v.begin()
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define FOR1(a) for (int _ = 0; _ < (a); ++_)
#define FOR2(i, a) for (int i = 0; i < (a); ++i)
#define FOR3(i, a, b) for (int i = (a); i < (b); ++i)
#define RFOR1(a) for (int _ = (a)-1; _ >= 0; --_)
#define RFOR2(i, a) for (int i = (a)-1; i >= 0; --i)
#define RFOR3(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define overload3(a, b, c, d, ...) d
// Always choose the fourth argument to call. Hence, which function to call is determined by the number of given arguments.
#define REP(...) overload3(__VA_ARGS__, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define RREP(...) overload3(__VA_ARGS__, RFOR3, RFOR2, RFOR1)(__VA_ARGS__)
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vb> vvb;
typedef vector<vc> vvc;
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
typedef queue<int> qi;
typedef queue<ll> qll;
typedef queue<pii> qpii;
typedef queue<pll> qpll;
typedef deque<int> dqi;
typedef deque<ll> dqll;
typedef deque<pii> dqpii;
typedef deque<pll> dqpll;
typedef priority_queue<int> pqi;
typedef priority_queue<ll> pqll;
typedef priority_queue<pii> pqpii;
typedef priority_queue<pll> pqpll;
typedef priority_queue<int, vi, greater<int> > r_pqi;
typedef priority_queue<ll, vll, greater<ll> > r_pqll;
typedef priority_queue<pii, vpii, greater<pii> > r_pqpii;
typedef priority_queue<pll, vpll, greater<pll> > r_pqpll;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m, q;
cin>>n>>m>>q;
vvi adj(n);
REP(i, m) {
int a, b;
cin>>a>>b;
adj[b-1].pushb(a-1);
}
int sq = 150;
vi from(n, -1);
vvpii rec(n);
REP(i, n) {
vi tmp;
tmp.reserve(n);
for(int v : adj[i]) {
for(auto [d, x] : rec[v]) {
if(from[x] == -1) {
tmp.pushb(x);
from[x] = d+1;
}
else {
chmax(from[x], d+1);
}
}
}
rec.reserve(n);
for(int v : tmp) {
rec[i].pushb(mp(from[v], v));
from[v] = -1;
}
rec[i].pushb(mp(0, i));
// cerr<<rec[i].size()<<endl;
sort(all(rec[i]), greater<pii>());
if(rec[i].size() > sq) {
rec[i].erase(rec[i].begin() + sq, rec[i].end());
}
}
vb block(n, 0);
REP(i, q) {
int t, l;
cin>>t>>l;
t--;
vi c(l);
REP(j, l) {
cin>>c[j];
c[j]--;
block[c[j]] = 1;
}
int ans = -1;
if(l < sq) {
// cerr<<endl;
for(auto [d, x] : rec[t]) {
// cerr<<d<<' '<<x<<endl;
if(block[x] == 0) {
ans = d;
break;
}
}
}
else {
vi dp(t+1, 0);
RREP(i, t+1) {
if(block[i] == 0) {
chmax(ans, dp[i]);
}
for(int v : adj[i]) {
chmax(dp[v], dp[i]+1);
}
}
}
cout<<ans<<endl;
REP(i, l) {
block[i] = 0;
}
}
}
