#include <bits/stdc++.h> #include <ext/rope> using namespace std; using namespace __gnu_cxx; #pragma GCC optimize("-Ofast") #pragma GCC optimize("-O1") //-------------------------------------------------------------// typedef long long ll; typedef unsigned long long ull; #define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define PI acos(-1) #define lb lower_bound #define ub upper_bound #define endl '\n' #define all(v) v.begin(),v.end() #define allr(v) v.rbegin(),v.rend() #define sum_to(n) (n*(n+1))/2 #define pb push_back #define pf push_front #define fil(arr,x) memset(arr,x,sizeof(arr)) const ll mod=1e9+7; int dx[8]={0,1,0,-1,1,1,-1,-1}; int dy[8]={1,0,-1,0,1,-1,-1,1}; //-------------------------------------------------------------// ll lcm(ll a,ll b) { return (max(a,b)/__gcd(a,b))*min(a,b); } void person_bool(bool x) { cout<<(x?"YES":"NO")<<endl; } const int N=1e5+5,B=316; vector<int>adj[N]; vector<pair<int,int>>vec[N]; int dp[N]; bool vis[N]; int temp[N]; bool deleted[N]; bool g[N]; vector<int>dist[N]; void dfs(int node){ vis[node]=1; for(auto i:adj[node]) if(!vis[i]) dfs(i); vector<int>k; for(auto i:adj[node]) for(auto j:vec[i]) temp[j.first]=max(temp[j.first],j.second+1),k.push_back(j.first); k.push_back(node); int mx=0; for(auto i:k){ if(!g[i]){ g[i]=1; dist[temp[i]].push_back(i); mx=max(mx,temp[i]); } } for(int i=mx;i>=0;i--){ for(auto j:dist[i]){ if(vec[node].size()==B)break; vec[node].push_back({j,i}); } if(vec[node].size()==B)break; } for(auto i:k){ g[i]=0; dist[temp[i]].clear(); temp[i]=0; } } int main() { //freopen("input.txt","r",stdin); //freopen("output.txt","w",stdout); fast int n,m,q; cin>>n>>m>>q; for(int i=0;i<m;i++){ int u,v; cin>>u>>v; adj[v].push_back(u); } for(int i=1;i<=n;i++) if(!vis[i]) dfs(i); while(q--){ int t,y; cin>>t>>y; vector<int>c; for(int i=0;i<y;i++){ int x; cin>>x; if(x<=t)c.push_back(x),deleted[x]=1; } y=c.size(); if(y<B){ int ans=-1; for(auto i:vec[t]){ if(!deleted[i.first]){ ans=i.second; break; } } cout<<ans<<endl; } else{ fil(dp,-1); for(int i=1;i<=t;i++){ if(!deleted[i])dp[i]=0; for(auto j:adj[i]) dp[i]=max(dp[i],(dp[j]>0?dp[j]+1:deleted[j]?deleted[i]*-1:1)); } cout<<dp[t]<<endl; } for(auto i:c)deleted[i]=0; } return 0; }