#include <bits/stdc++.h>
using namespace std;
#define name "bitaro_parties"
#define MAXN 100005
#define pb push_back
#define pf push_front
#define ll long long
#define ii pair<int, int>
#define fs first
#define sc second
#define ill pair<int, ll>
#define lli pair<ll, int>
#define llll pair<ll, ll>
#define all(v) v.begin(),v.end()
#define uni(v) v.erase(unique(all(v)),v.end())
#define bit(n,i) (((n)>>(i))&1)
#define FOR(i,a,b) for (int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for (int i=(a),_b=(b); i>=_b; i--)
#define MASK(i) (1LL<<(i))
const int INF=1e9;
const int MOD=1e9+7;
void add(int &u, int v){
u+=v;
if (u>=MOD) u-=MOD;
}
void sub(int &u, int v){
u-=v;
if (u<0) u+=MOD;
}
void minimize(int &u, int v){
u=min(u,v);
}
void maximize(int &u, int v){
u=max(u,v);
}
long long Rand(long long l, long long r){
ll tmp=0;
FOR(i,1,4) tmp=((tmp<<15)^(((1<<15)-1)&rand()));
return l+tmp%(r-l+1);
}
int n,m,q;
vector<int> adj[MAXN];
vector<ii> opt[MAXN];
const int BLOCKS=100;
int mark[MAXN];
int dp[MAXN];
queue<int> Q;
int a[MAXN];
int calc(int r){
FOR(i,1,r) dp[i]=-INF;
FOR(i,1,r){
if (mark[i]==0) dp[i]=0;
for (int j:adj[i]){
maximize(dp[i],dp[j]+1);
}
}
return (dp[r]>=0?dp[r]:-1);
}
int main()
{
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin>>n>>m>>q;
FOR(i,1,m){
int x,y;
cin>>x>>y;
adj[y].pb(x);
}
memset(mark,-1,sizeof(mark));
FOR(i,1,n){
opt[i].pb({0,i});
for (int j:adj[i]){
for (ii pairs: opt[j]){
int d=pairs.fs,u=pairs.sc;
if (mark[u]>=0){
maximize(opt[i][mark[u]].fs,d+1);
}
else{
mark[u]=(int)opt[i].size();
opt[i].pb({d+1,u});
}
}
}
sort(all(opt[i]),greater<ii>());
while ((int)opt[i].size()>BLOCKS){
ii tmp=opt[i].back();
mark[tmp.sc]=-1;
opt[i].pop_back();
}
FOR(j,0,(int)opt[i].size()-1) mark[opt[i][j].sc]=-1;
}
memset(mark,0,sizeof(mark));
while (q--){
int u,sz;
cin>>u>>sz;
FOR(i,1,sz) cin>>a[i];
FOR(i,1,sz) mark[a[i]]=1;
if (sz>=BLOCKS){
cout<<calc(u)<<"\n";
}
else{
int ans=-1;
FOR(i,0,(int)opt[u].size()-1){
if (mark[opt[u][i].sc]==0){
ans=opt[u][i].fs;
break;
}
}
cout<<ans<<"\n";
}
FOR(i,1,sz) mark[a[i]]=0;
}
return 0;
}
