#include<bits/stdc++.h>
using namespace std;
#define N 100010
#define ff first
#define ss second
#define pb push_back
#define pii pair<int,int>
int B ;
int not_taken[N];
vector<int>gr[N];
vector<int>grr[N];
int dp[N];
bitset<N>rep;
vector<pii>dist[N];
vector<pii>child_and_dist;
bool compare(const pii &p1, const pii & p2)
{
return p1.first > p2.first;
}
int32_t main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n, m, q;
cin >> n >> m >> q;
B = sqrt(n);
B += 100;
int a, b;
for (int i = 1; i <= m; i++)
{
cin >> a >> b;
gr[a].pb(b);
grr[b].pb(a);
}
///// precomputation
for (int node = 1; node <= n; node++)
{
child_and_dist.clear();
for (auto child : grr[node])
{
for (auto j : dist[child])
{
child_and_dist.pb({j.ff + 1, j.ss});
}
}
child_and_dist.pb({0, node});
int num_taken = 0;
sort(child_and_dist.begin(), child_and_dist.end(), compare);
for (int j = 0; j < (int)child_and_dist.size() && num_taken < B; j++)
{
if (!rep[child_and_dist[j].ss])
{
num_taken++;
dist[node].pb({child_and_dist[j]});
rep[child_and_dist[j].ss] = 1;
}
}
for (int j = 0; j < (int)dist[node].size(); j++)
rep[dist[node][j].ss] = 0;
}
for (int i = 0; i <= n; i++)
not_taken[i] = 0;
while (q--)
{
int p, q2;
cin >> p >> q2;
for (int i = 1; i <= q2; i++)
{
int r; cin >> r;
not_taken[r] = q;
}
///////////////////////////
if (q < B)
{
int ans = -1;
for (auto i : dist[p])
{
if (not_taken[i.second] == q )
continue;
ans = i.first;
break;
}
cout << ans << '\n';
}
else
{
for (int i = 1; i <= p; i++)
{
dp[i] = 0;
}
for (int i = 1; i <= p; i++)
{
if (not_taken[i] == q && dp[i] == 0)
continue;
for (auto child : gr[i])
{
dp[child] = max(dp[child], dp[i] + 1);
}
}
if (not_taken[p] == q && dp[p] == 0)
dp[p] = -1;
cout << dp[p] << '\n';
}
}
}
