#include <bits/stdc++.h>
using namespace std;
#define int long long
///#define endl '\n'
const int maxn=2e5+10;
const int sz=100;
const int mod=1e9+7;
vector<int>g[maxn];
vector<int>rg[maxn];
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
///freopen("dulciuri.in","r",stdin);
///freopen("dulciuri.out","w",stdout);
int n,m,q;
cin>>n>>m>>q;
for(int i=0;i<m;i++)
{
int a,b;
cin>>a>>b;
g[a].push_back(b);
rg[b].push_back(a);
}
vector<vector<pair<int,int>>>l(n+1);
vector<int>vis(n+1,-1);
l[1]={{0,1}};
for(int i=2;i<=n;i++)
{
vector<int>v;
for(auto sosed:rg[i])
{
for(auto ax:l[sosed])
{
int dist=ax.first;
int node=ax.second;
if(vis[node]<0)
{
v.push_back(node);
}
vis[node]=max(vis[node],dist+1);
}
}
l[i].emplace_back(0,i);
for(auto ax:v)
{
l[i].emplace_back(vis[ax],ax);
}
sort(l[i].begin(),l[i].end(),greater<>());
if(l[i].size()>sz)
{
l[i].resize(sz);
}
for(auto ax:v)
{
vis[ax]=-1;
}
}
for(int i=0;i<q;i++)
{
int t,y;
cin>>t>>y;
vector<int>b(y);
for(int j=0;j<y;j++)
{
cin>>b[j];
}
set<int>bs(b.begin(),b.end());
if(y>=sz)
{
vector<int>dp(t+1,-1);
dp[t]=0;
for(int node=t;node>=1;node--)
{
if(dp[node]==-1)continue;
for(auto sosed:rg[node])
{
dp[sosed]=max(dp[sosed],dp[node]+1);
}
}
int mx=-1;
for(int node=1;node<=t;node++)
{
if(!bs.count(node))
{
mx=max(mx,dp[node]);
}
}
cout<<mx<<endl;
}
else
{
int mx=-1;
for(auto ax:l[t])
{
int dist=ax.first;
int node=ax.second;
if(!bs.count(node))
{
mx=max(mx, dist);
}
}
cout<<mx<<endl;
}
}
return 0;
}
