#include <bits/stdc++.h>
#define int long long
using namespace std;
using vi = vector<int>;
using pi = pair<int,int>;
using ll = long long;
const int B = 100;
void solve() {
int n, m, q;
cin >> n >> m >> q;
vector<vi>adjL(n+1);
vector<vector<pi>>paths(n+1);
for(int i=0; i<m; ++i) {
int x, y;
cin >> x >> y;
adjL[y].push_back(x);
}
vi from(n+1, -1);
for(int i=1; i<=n; ++i) {
vi idx;
for(int adj: adjL[i]) {
for(pi p: paths[adj]) {
if(from[p.second] == -1) idx.push_back(p.second);
from[p.second] = max(from[p.second], p.first + 1);
}
}
paths[i].push_back({0, i});
for(int j: idx) paths[i].push_back({from[j], j});
sort(paths[i].rbegin(), paths[i].rend());
while(paths[i].size() > B) paths[i].pop_back();
for(int j: idx) from[j] = -1;
}
vi blk(n+1, -1);
for(int i=0; i<q; ++i) {
int t, num;
cin >> t >> num;
for(int j=0; j<num; ++j) {
int tmp;
cin >> tmp;
blk[tmp] = i;
}
int ans = -1;
if(num >= B) {
vi dp(t+1, 0);
for(int j=t; j>=1; --j) {
if(!dp[j] && j != t) continue;
if(blk[j] != i) ans = max(ans, dp[j]);
for(int adj: adjL[j]) {
dp[adj] = max(dp[adj], dp[j] + 1);
}
}
cout << ans << endl;
} else {
for(int j=0; j<paths[t].size(); ++j) {
int tmp = paths[t][j].second;
if(blk[tmp] != i) {
ans = paths[t][j].first;
break;
}
}
cout << ans << endl;
}
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int t = 1;
while(t--) solve();
return 0;
}
