#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define Sz(x) int((x).size())
#define all(x) x.begin(), x.end()
#define fi first
#define se second
#define cl clear
const int maxn = 1e5 + 10;
const int maxa = 2e9 + 5;
const int mod = 1e9 + 7;
const ll inf = 2e18;
const double eps = 1e-9;
vector <int> vc, adj[maxn], ajd[maxn];
vector <pair <int, int> > mx[maxn];
bool f[maxn], mark[maxn];
int dp[maxn], sq;
inline void dfs(int v){
mark[v] = 1;
mx[v].pb({0, v});
for (int u : ajd[v]){
if(!mark[u]) dfs(u);
vector <pair <int, int> > vc = mx[v], uc = mx[u];
for (int i = 0; i < Sz(uc); i ++) uc[i].fi ++;
mx[v].cl();
int p1 = 0, p2 = 0;
while (p1 < Sz(vc) || p2 < Sz(uc)){
if(p2 == Sz(uc) || (p1 < Sz(vc) && vc[p1].fi > uc[p2].fi)){
if(!f[vc[p1].se]) mx[v].pb(vc[p1]), f[vc[p1].se] = 1;
p1 ++;
}
else{
if(!f[uc[p2].se]) mx[v].pb(uc[p2]), f[uc[p2].se] = 1;
p2 ++;
}
}
for (auto p : mx[v]) f[p.se] = 0;
while (Sz(mx[v]) > sq) mx[v].pop_back();
}
return;
}
int main(){
ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
int n, m, q;
cin >> n >> m >> q;
sq = sqrt(n);
for (int i = 0; i < m; i ++){
int v, u;
cin >> v >> u;
adj[v].pb(u);
ajd[u].pb(v);
}
for (int i = n; i >= 1; i --){
if(!mark[i]) dfs(i);
}
while(q --){
int t, y;
cin >> t >> y;
vc.cl();
for (int i = 0; i < y; i ++){
int c;
cin >> c;
vc.pb(c);
for (int c : vc) f[c] = 1;
}
int ans = -1;
if(y >= sq){
fill(dp, dp + n + 10, -mod);
dp[t] = 0;
for (int i = t; i >= 1; i --){
for (int j : adj[i]) dp[i] = max(dp[i], dp[j] + 1);
if(!f[i]) ans = max(ans, dp[i]);
}
}
else{
for (auto p : mx[t]) if(!f[p.se]) ans = max(ans, p.fi);
}
for (int c : vc) f[c] = 0;
cout << ans << '\n';
}
return 0;
}
