/*
== ==
<^\()/^> <^\()/^>
\/ \/ \/ \/
/__\ . ' . /__\
== /\ . | . /\ ==
<^\()/^> !_\/ ' | ' \/_! <^\()/^>
\/ \/ !_/I_|| . ' \'/ ' . ||_I\_! \/ \/
/__\ /I_/| || -==C++==- || |\_I\ /__\
/_ \ !//| | || ' . /.\ . ' || | |\\! /_ \
(- ) /I/ | | || . | . || | | \I\ (= )
\__/!//| | | || ' | ' || | | |\\!\__/
/ \I/ | | | || ' . ' * || | | | \I/ \
{_ __} | | | || || | | | {____}
_!__|= || | | | || * + || | | | || |__!_
_I__| ||__|__|__|_|| A ||_|__|__|__||- |__I_
-|--|- ||--|--|--|-|| __/_\__ * ||-|--|--|--||= |--|-
| | || | | | || /\-'o'-/\ || | | | || | |
| |= || | | | || _||:<_>:||_ || | | | ||= | |
| |- || | | | || * /\_/=====\_/\ * || | | | ||= | |
| |- || | | | || __|:_:_[I]_:_:|__ || | | | ||- | |
_|__| ||__|__|__|_||:::::::::::::::::::::||_|__|__|__|| |__|_
-|--|= ||--|--|--|-||:::::::::::::::::::::||-|--|--|--||- |--|-
jgs|- || | | | ||:::::::::::::::::::::|| | | | ||= | |
~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^~~~~~~~~~
*/
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ff first
#define ss second
void steroids() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
std::cout.tie(0);
}
const int BLOCK_SIZE = 100;
int main() {
steroids();
int n, m, q;
std::cin >> n >> m >> q;
std::vector<std::vector<int>>radj(n);
for (int i = 0; i < m; i++) {
int u, v;
std::cin >> u >> v;
u--; v--;
radj[v].push_back(u);
}
std::vector<std::vector<std::pair<int, int>>> longest(n);
std::vector<int> dist(n, -1);
for (int i = 0; i < n; i++) {
longest[i].push_back({0, i});
std::vector<int> reachable;
for (const int &v : radj[i]) {
for (const std::pair<int, int> &p : longest[v]) {
if (dist[p.ss] == -1) {
reachable.push_back(p.ss);
dist[p.ss] = p.ff + 1;
} else {
dist[p.ss] = std::max(dist[p.ss], p.ff + 1);
}
}
}
for (const int &r : reachable) { longest[i].push_back({dist[r], r});}
std::sort(longest[i].rbegin(), longest[i].rend());
while (longest[i].size() > BLOCK_SIZE) { longest[i].pop_back();}
for (const int &r : reachable) dist[r] = -1;
}
std::vector<bool> is_blocked(n);
for (int i = 0; i < q; i++) {
int t, y;
std::cin >> t >> y;
t--;
std::vector<int> blocked_town(y);
for (int j = 0; j < y; j++) {
std::cin >> blocked_town[j];
is_blocked[--blocked_town[j]] = true;
}
int ans = -1;
if (y >= BLOCK_SIZE) {
std::vector<int> dp(t+1, -1);
dp[t] = 0;
for (int i = t; i >= 0; i--) {
if (dp[i] == -1) continue;
if (!is_blocked[i]) { ans = std::max(ans, dp[i]);}
for (const int &j : radj[i]) { dp[j] = std::max(dp[j], dp[i] + 1); }
}
} else {
for (const std::pair<int, int> &p : longest[t]) {
if (!is_blocked[p.ss]) {
ans = p.ff;
break;
}
}
}
std::cout << ans << '\n';
for (const int &a : blocked_town) is_blocked[a] = false;
}
}
