#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pi = pair<int, int>;
using pl = pair<long long, long long>;
using vi = vector<int>;
using vl = vector<long long>;
using vpi = vector<pair<int, int>>;
using vpl = vector<pair<long long, long long>>;
#define fur(i, a, b) for(ll i = a; i <= (ll)b; ++i)
#define ruf(i, a, b) for(ll i = a; i >= (ll)b; --i)
#define fr first
#define sc second
#define mp make_pair
#define pb emplace_back
#define nl "\n"
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
const ll inf = 1e18L;
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
ll n, m, q;
cin >> n >> m >> q;
vl adj[n + 1];
fur(i, 1, m) {
ll l, r;
cin >> l >> r;
adj[l].pb(r);
}
while(q--) {
ll t, y;
cin >> t >> y;
set<ll> s;
fur(rep, 1, y) {
ll a;
cin >> a;
s.insert(a);
}
ll dp[n + 1];
fur(i, 1, n) {
if(!s.count(i) && i <= t) {
dp[i] = 0;
} else {
dp[i] = -inf;
}
}
fur(i, 1, t) {
for(auto j : adj[i]) {
dp[j] = max(dp[j], dp[i] + 1);
}
}
cout << (dp[t] < 0 ? -1 : dp[t]) << nl;
}
}
