#include<bits/stdc++.h>
#define fo(i,d,c) for(int i=d;i<=c;i++)
#define fod(i,c,d) for(int i=c;i>=d;i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout<<"\n";
#define int long long
#define inf 1000000000
#define pii pair<int,int>
#define vii vector<pii>
#define lb(x) x&-x
#define bit(i,j) ((i>>j)&1)
#define offbit(i,j) (i^(1<<j))
#define onbit(i,j) (i|(1<<j))
#define vi vector<int>
template <typename T1, typename T2> bool minimize(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
using namespace std;
int n,m,q;
const int nsqrt = 450;
vi ke[maxn];
vii d[maxn];
int dist[maxn];
bool ok[maxn];
bool vis[maxn];
int from[maxn];
int val[maxn];
main()
{
#define name "TASK"
if(fopen(name".inp","r"))
{
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m >> q;
fo(i,1,m)
{
int u,v;
cin >> u >> v;
ke[v].pb(u);
}
fo(u,1,n)
{
vi now;
for(int v : ke[u])
{
for(auto [z,t] : d[v])
{
if(from[z] == u)
val[z] = max(val[z],t + 1);
else
{
from[z] = u;
val[z] = t + 1;
now.pb(z);
}
}
}
d[u].pb(u,0);
for(int it : now) d[u].pb(it,val[it]);
sort(d[u].begin(),d[u].end(),[](pii a,pii b)
{
return a.se > b.se or (a.se == b.se and a.fi > b.fi);
});
if(d[u].size() > nsqrt) d[u].erase(d[u].begin() + nsqrt,d[u].end());
}
while(q--)
{
int ans = -1;
int t,s;
cin >> t >> s;
vi bad(s);
for(int &it : bad)
{
cin >> it;
ok[it] = 1;
}
if(s > nsqrt)
{
fod(u,n,1) dist[u] = -1;
fod(u,t,1)
{
if(!ok[u])
ans = max(ans,dist[u]);
for(int v : ke[u])
{
dist[v] = max(dist[v],dist[u] + 1);
}
}
}
else
{
for(auto [i,j] : d[t])
{
if(!ok[i])
{
ans = j;
break;
}
}
}
for(int it : bad) ok[it] = 0;
cout << ans;en;
}
}
