#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
using namespace std;
#define F first
#define S second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define SZ(x) (int)(x).size()
//#define int ll
const int N = 1e5 + 10;
const int B = 100;
const int INF = 1e9 + 10;
vector<pair<int, int>> best[N];
vector<int> g[N];
int used[N], timer, dp[N], ptr[N];
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m, q;
cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
g[v].pb(u);
}
for (int i = 1; i <= n; i++) {
timer++;
set<pair<int, int>> st;
for (int v : g[i]) {
ptr[v] = 0;
st.insert({-best[v][0].F, v});
}
while (!st.empty() && SZ(best[i]) < B) {
int v = st.begin()->S;
st.erase(st.begin());
if (used[best[v][ptr[v]].S] < timer) {
used[best[v][ptr[v]].S] = timer;
best[i].pb(make_pair(best[v][ptr[v]].F + 1, best[v][ptr[v]].S));
}
ptr[v]++;
if (ptr[v] < SZ(best[v])) {
st.insert(make_pair(-best[v][ptr[v]].F, v));
}
}
if (SZ(best[i]) < B) {
best[i].pb(make_pair(0, i));
}
}
for (int i = 0; i < q; i++) {
int v;
cin >> v;
int cnt;
cin >> cnt;
timer++;
for (int j = 0; j < cnt; j++) {
int x;
cin >> x;
used[x] = timer;
}
if (cnt < B) {
int res = -1;
for (auto it : best[v]) {
if (used[it.S] < timer) {
res = it.F;
break;
}
}
cout << res << '\n';
}
else {
for (int i = 1; i <= v; i++) {
if (used[i] == timer) {
dp[i] = -INF;
}
else {
dp[i] = 0;
}
for (int v : g[i]) {
dp[i] = max(dp[i], dp[v] + 1);
}
//cout << dp[i] << ' ';
}
//cout << '\n';
cout << (dp[v] < 0 ? -1 : dp[v]) << '\n';
}
}
}
