#include <bits/stdc++.h>
using namespace std;
#define file "test"
#define ll long long
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define all(v) (v).begin(), (v).end()
const int N=1e5+2;
int n,m,q,dp[N];
vector<int> E[N];
vector<pii> f[N];
int main()
{
//freopen(file".inp", "r", stdin);
//freopen(file".out", "w", stdout);
ios_base::sync_with_stdio(0); cin.tie(0);
cin>>n>>m>>q;
for (int i=1;i<=m;i++)
{
int u,v; cin>>u>>v; E[v].pb(u);
}
for (int i=1;i<=n;i++)
{
f[i].pb({0, i});
vector<int> tmp, dis(n+1, -1);
for (int j : E[i]) for (pii p : f[j])
{
int u=p.second, w=p.first;
if (dis[u] == -1)
{
tmp.pb(u); dis[u]=w+1;
}
else dis[u]=max(dis[u], w+1);
}
for (int u : tmp) f[i].pb({dis[u], u});
sort(f[i].rbegin(), f[i].rend());
while (f[i].size() > 100) f[i].pop_back();
}
while (q--)
{
int t,k; cin>>t>>k;
vector<bool> ok(n+1, 0); for (int i=1;i<=k;i++) {int x; cin>>x; ok[x]=1;}
if (k >= 100)
{
int res=-1;
for (int i=t;i>=1;i--) dp[i]=0;
for (int i=t;i>=1;i--)
{
if (ok[i]) continue;
res=max(res, dp[i]);
for (int v : E[i]) dp[v]=max(dp[v], dp[i]+1);
}
cout<<res<<'\n';
}
else {
int res=-1;
for (pii p : f[t]) if (!ok[p.second]) {res=p.first; break;}
cout<<res<<'\n';
}
}
}
