#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int SQ = 100;
vector<int> adj[100001], rAdj[100001];
bool visited[100001], processed[100001];
vector<pair<int, int>> longest[100001]; // len, node
int best[100001];
set<int> ys;
void process(int node)
{
if (processed[node])
return;
processed[node] = true;
auto& x = longest[node];
for (int u : rAdj[node])
{
process(u);
for (auto& [v, len] : longest[u])
x.push_back({v, len + 1});
x.push_back({u, 1});
}
x.push_back({node, 0});
sort(x.begin(), x.end(), [](auto& a, auto& b)
{
if (a.first != b.first)
return a.first < b.first;
return a.second > b.second;
});
x.erase(unique(x.begin(), x.end(), [](auto& a, auto& b) { return a.first == b.first; }), x.end());
sort(x.begin(), x.end(), [](auto& a, auto& b) { return a.second > b.second; });
if (x.size() > SQ)
x.resize(SQ);
}
void dfs2(int node)
{
if (visited[node])
return;
visited[node] = true;
process(node);
for (int u : adj[node])
dfs2(u);
}
void dfs(int node)
{
visited[node] = true;
best[node] = -1;
for (int u : rAdj[node])
{
if (!visited[u])
dfs(u);
if (best[u] != -1)
best[node] = max(best[node], best[u] + 1);
}
if (!ys.count(node))
best[node] = max(best[node], 0);
}
int main()
{
cin.tie(NULL) -> sync_with_stdio(false);
int N, M, Q;
cin >> N >> M >> Q;
while (M--)
{
int a, b;
cin >> a >> b;
adj[a].push_back(b);
rAdj[b].push_back(a);
}
for (int i = 1; i <= N; ++i)
dfs2(i);
while (Q--)
{
int t, y, x;
cin >> t >> y;
ys.clear();
for (int i = 0; i < y; ++i)
{
cin >> x;
ys.insert(x);
}
if (y < SQ)
{
int mx = -1;
for (auto& [u, len] : longest[t])
if (!ys.count(u))
{
mx = len;
break;
}
cout << mx << '\n';
}
else
{
memset(visited, 0, sizeof visited);
dfs(t);
cout << best[t] << '\n';
}
}
return 0;
} /*****************************=
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