// #pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 998244353;
const ll inf = 2e18;
const ll B = 320;
const ll N = 1e5+8;
int n,m,q;
vector<int> g[N];
vector<pair<int,int>> best[N];
int d[N],vst[N],bad[N],dp[N];
void solve(){
cin >> n >> m >> q;
for(int i = 1; i <= m; i++){
int u,v;cin >> u >> v;
g[v].pb(u);
}
for(int u = 1; u <= n; u++){
vector<int> cur;
for(int v:g[u]){
for(pair<int,int> ed:best[v]){
int vv = ed.se, w = ed.fi;
if(vst[vv] == u) d[vv] = max(d[vv],w+1);
else{
vst[vv] = u;
d[vv] = w+1;
cur.pb(vv);
}
}
}
for(int v:cur) best[u].pb({d[v],v});
best[u].pb({0,u});
sort(all(best[u]),greater<pair<int,int>>());
while(best[u].size() > B) best[u].pop_back();
}
while(q--){
int t,s;cin >> t >> s;
for(int i = 1; i <= s; i++){
int x;cin >> x;
bad[x] = q;
}
int ans = -1;
if(s < B){
for(pair<int,int> v:best[t]){
if(bad[v.se] != q){
ans = v.fi;
break;
}
}
}
else{
fill(dp,dp+n+1,-1);
for(int u = 1; u <= t; u++){
if(bad[u] != q) dp[u] = 0;
for(int v:g[u]){
if(dp[v] != -1) dp[u] = max(dp[u],dp[v]+1);
}
}
ans = dp[t];
}
cout << ans << '\n';
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// if (fopen("test.inp", "r")) {
// freopen("test.inp", "r", stdin);
// freopen("test.out", "w", stdout);
// }
ll T = 1;
// cin >> T;
for (ll i = 1; i <= T; i++) {
solve();
cout << '\n';
}
}
