#include <bits/stdc++.h>
using namespace std;
using pi = pair<int, int>;
int BLOCK;
void build_dist_arr(int node,
const vector<vector<int>> &adj,
vector<set<pi, greater<pi>>> &anc,
vector<unordered_map<int, int>> &act)
{
anc[node].insert({0, node});
for (auto &child : adj[node])
{
for (auto &[dist, from_node] : anc[node])
{
if (act[child][from_node] == 0)
{
anc[child].insert({dist + 1, from_node});
act[child][from_node] = dist + 1;
}
else
{
if (act[child][from_node] < dist + 1)
{
anc[child].erase({act[child][from_node], from_node});
anc[child].insert({dist + 1, from_node});
act[child][from_node] = dist + 1;
}
}
if (anc[child].size() > BLOCK)
{
act[child][(*anc[child].rbegin()).second] = 0;
anc[child].erase(prev(anc[child].end()));
}
}
}
for (auto &child : adj[node])
{
build_dist_arr(child, adj, anc, act);
}
}
int search(int node, const vector<vector<int>> &adj, const unordered_set<int> &busy)
{
vector<int> mx(node + 1, 0);
for (int i = 0; i < node; i++)
{
for (auto &child : adj[i])
{
if (child > node)
continue;
if (busy.count(i) == 0 || mx[i] > 0)
mx[child] = max(mx[child], mx[i] + 1);
}
}
if (mx[node] == 0)
{
if (busy.count(node))
return -1;
}
return mx[node];
}
int scan(int node, const vector<set<pi, greater<pi>>> &anc, const unordered_set<int> &busy)
{
for (auto &[dist, from] : anc[node])
{
if (busy.count(from))
continue;
return dist;
}
return -1;
}
int main()
{
#if defined(DEBUG)
freopen("test.in", "r", stdin);
freopen("test.out", "w", stdout);
#else
cin.tie(0)->sync_with_stdio(false);
#endif
int N, M, Q;
cin >> N >> M >> Q;
BLOCK = (int)sqrt(Q);
vector<vector<int>> adj(N);
for (int i = 0; i < M; i++)
{
int a, b;
cin >> a >> b;
a--, b--;
adj[a].push_back(b);
}
vector<set<pi, greater<pi>>> ancestors(N);
vector<unordered_map<int, int>> anc_ct(N);
build_dist_arr(0, adj, ancestors, anc_ct);
for (int q = 0; q < Q; q++)
{
int T, Y;
cin >> T >> Y;
T--;
unordered_set<int> busy;
for (int _ = 0; _ < Y; _++)
{
int y;
cin >> y;
y--;
busy.insert(y);
}
if (Y >= BLOCK)
{
cout << search(T, adj, busy) << "\n";
}
else
{
cout << scan(T, ancestors, busy) << "\n";
}
}
cout << flush;
}
