#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define F first
#define S second
#define forn(i, n) for(int i = 0; i < n; ++i)
#define forbn(i, b, n) for(int i = b; i < n; ++i)
#define sz(v) (int)v.size()
#define pb push_back
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define min3(a, b, c) min(a, min(b, c))
#define at(m, k) (m.find(k) != m.end() ? m[k]: 0)
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long long ll;
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
template <class T> inline void mineq(T &a, T b) { a = min(a, b); }
template <class T> inline void maxeq(T &a, T b) { a = max(a, b); }
const int MX = 100 * 1000 + 10;
int sq = 100;
vi gr[MX];
vii farthest[MX];
bool busy[MX];
bool att[MX];
bool used[MX];
vi d1;
int dfs1(int node) {
if(d1[node] != -1) return d1[node];
int mx = 0;
for(int nb: gr[node]) {
if(busy[nb]) {
int val = dfs1(nb);
if(val)
maxeq(mx, val + 1);
}
else
maxeq(mx, dfs1(nb) + 1);
}
d1[node] = mx;
return mx;
}
void dfs2(int node) {
if(att[node]) return;
att[node] = true;
vii ans;
ans.eb(0, node);
for(int nb: gr[node]) {
dfs2(nb);
for(ii p: farthest[nb]) {
used[p.S] = false;
ans.eb(p.F + 1, p.S);
}
}
sort(all(ans), greater<ii>());
for(ii p: ans) {
if(!used[p.S]) {
used[p.S] = true;
farthest[node].pb(p);
if(sz(farthest[node]) >= sq)
break;
}
}
}
void solve() {
int n, m, q;
cin >> n >> m >> q;
forn(_, m) {
int a, b;
cin >> a >> b;
gr[b].pb(a);
}
forbn(node, 1, n + 1)
dfs2(node);
forn(_, q) {
int t, Y;
cin >> t >> Y;
vi ys(Y);
forn(j, Y) {
cin >> ys[j];
busy[ys[j]] = true;
}
if(Y >= sq) {
d1.assign(n + 1, -1);
int val = dfs1(t);
if(val == 0 && busy[t])
cout << -1 << '\n';
else
cout << val << '\n';
} else {
bool printed = false;
for(ii node: farthest[t]) {
if(!busy[node.S]) {
cout << node.F << '\n';
printed = true;
break;
}
}
if(!printed)
cout << -1 << '\n';
}
for(int y: ys)
busy[y] = false;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
// freopen("haybales.in", "r", stdin);
// freopen("haybales.out", "w", stdout);
int t = 1;
// cin >> t;
while(t--) {
solve();
}
}
