/*
VENI VIDI VICI
*/
// #pragma GCC optimize("Ofast","unroll-all-loops","fast-math","no-stack-protector","give-no-fuck")
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <algorithm>
// #include <set>
// #include <map>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define rep(i,x, n) for (int i = (x); i < (n); ++i)
#define repr(i,x, n) for (int i = (n) - 1; i >= (x); --i)
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());
// #define sum accumulate
//using i128 = __int128;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vi>;
using sll = set<ll>;
template<class T>
istream& operator>>(istream& is, vector<T>& v) {
for(auto &i:v) is>>i;
return is;
}
template<class T1,class T2>
istream& operator>>(istream& is, pair<T1,T2>& p) {
is>>p.fi>>p.se;
return is;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
for(const auto &i:v) os<<i<<' ';
return os;
}
template<class T1,class T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p) {
os<<p.fi<<' '<<p.se; return os;
}
void pyn(bool x)
{
cout<<(x?"YES":"NO")<<endl;
}
void pYN(bool x)
{
cout<<(x?"Yes":"No")<<endl;
}
void pAB(bool x)
{
cout<<(x?"Alice":"Bob")<<endl;
}
ll powmod(ll a,ll b,ll modulo)
{
if(b==0){
return 1;
}
ll temp=powmod(a,b/2,modulo);
if(b%2==0){
return (temp*temp)%modulo;
}
else{
return (a*((temp*temp)%modulo))%modulo;
}
}
bool Prime(ll n){
for (ll i = 2; i*i <= n; i++)
if (n % i == 0)
return false;
return (n>1);
}
void readIO() {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
void solve();
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// readIO();
int uwu=1;
// cin>>uwu;
for(int tc=1;tc<=uwu;tc++) {
// cout<<"Case #"<<tc<<": ";
solve();
}
return 0;
}
const int N=1e5+100,B=100;
vl ma[N],rma[N];
ll dp[N];
bool vis[N],qry[N];
vector<pair<int,int>> cur[N],temp;
void solve()
{
ll n,m,q;
cin>>n>>m>>q;
for(int i=0;i<m;i++)
{
int s,e;
cin>>s>>e;
ma[s].pb(e);
rma[e].pb(s);
}
for(int i=1;i<=n;i++)
{
cur[i].push_back({0,i});
for(auto p:rma[i]) // O(m)
{
temp.clear();
int l1=0,l2=0;
// sll nodes;
while(l1<cur[i].size() and l2<cur[p].size() and temp.size()<B)
{
// if(nodes.find(cur[i][l1].second)!=nodes.end())
if(vis[cur[i][l1].second])
{
l1++;
continue;
}
// if(nodes.find(cur[p][l2].second)!=nodes.end())
if(vis[cur[p][l2].second])
{
l2++;
continue;
}
if(cur[i][l1].first>=(cur[p][l2].first+1))
{
// nodes.insert(cur[i][l1].second);
vis[cur[i][l1].second]=1;
temp.push_back(cur[i][l1]);
l1++;
}
else
{
// nodes.insert(cur[p][l2].second);
vis[cur[p][l2].second]=1;
temp.push_back({cur[p][l2].first+1,cur[p][l2].second});
l2++;
}
}
while(l1<cur[i].size() and temp.size()<B)
{
// if(nodes.find(cur[i][l1].second)!=nodes.end())
if(vis[cur[i][l1].second])
{
l1++;
continue;
}
// nodes.insert(cur[i][l1].second);
vis[cur[i][l1].second]=1;
temp.push_back(cur[i][l1]);
l1++;
}
while(l2<cur[p].size() and temp.size()<B)
{
// if(nodes.find(cur[p][l2].second)!=nodes.end())
if(vis[cur[p][l2].second])
{
l2++;
continue;
}
// nodes.insert(cur[p][l2].second);
vis[cur[p][l2].second]=1;
temp.push_back({cur[p][l2].first+1,cur[p][l2].second});
l2++;
}
swap(cur[i],temp);
for(auto j:cur[i])
{
vis[j.second]=0;
}
}
}
//O(n*b*lgB)
while(q--)//O(n)
{
int t,sz;
cin>>t>>sz;
// sll bk;
vl bk;
for(int i=0;i<sz;i++)
{
ll x;
cin>>x;
qry[x]=1;
bk.pb(x);
}
if(sz<B)
{
ll ans=-1;
for(auto x:cur[t])
{
// cout<<x.first<<' '<<x.second<<endl;
if(!qry[x.second])
{
ans=max(ans,(ll)x.first);
}
}
cout<<ans<<endl;
}
else
{
for(int i=1;i<=n;i++)
{
dp[i]=-1;
}
dp[t]=0;
for(int i=t;i>=1;i--)
{
if(dp[i]==-1)continue;
// we want to update only from vertex reachiabl by t
for(auto y:rma[i])
{
dp[y]=max(dp[y],dp[i]+1);
}
}
ll mx=-1;
for(int i=1;i<=t;i++)
{
if(!qry[i]) // n lgn
{
mx=max(mx,dp[i]);
}
}
cout<<mx<<endl;
}
for(auto x:bk)
qry[x]=0;
}
}
