#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int SQ = 100;
const int MX = 100001;
vector<int> adj[MX], rAdj[MX];
bool visited[MX], processed[MX], blocked[MX];
vector<pair<int, int>> longest[MX]; // len, node
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);
}
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;
cin >> t >> y;
vector<int> temp(y);
for (int& i : temp)
cin >> i, blocked[i] = true;
if (y < SQ)
{
int mx = -1;
for (auto& [u, len] : longest[t])
if (!blocked[u])
{
mx = len;
break;
}
cout << mx << '\n';
}
else
{
vector<int> dp(t + 1, -1);
for (int i = 1; i <= t; ++i)
{
for (int u : rAdj[i])
if (dp[u] != -1)
dp[i] = max(dp[i], dp[u] + 1);
if (!blocked[i])
dp[i] = max(dp[i], 0);
}
cout << dp[t] << '\n';
}
for (int i : temp)
blocked[i] = false;
}
return 0;
} /*****************************=
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