#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define SZ(s) (int)s.size()
#define ff first
#define ss second
const int N = 1e5 + 5;
vector <int> v[N], vis, ds;
vector <pair <int, int>> V[N];
int k, ind[N], vis1[N];
void dfs(int x) {
if(ds[x] != -(1e9 + 1)) return;
ds[x] = (vis[x] ? 0 : -1e9);
for(auto i : v[x]) {
dfs(i);
ds[x] = max(ds[x], ds[i] + 1);
}
}
void f(int x) {
if(vis[x]) return;
vis[x] = true;
priority_queue <pair <pair <int, int>, int>> q;
for(auto i : v[x]) {
f(i);
q.push({V[i][0], i});
ind[i] = 0;
}
while(SZ(V[x]) < k and SZ(q)) {
auto [d, Y] = (q.top()).ff;
int y = (q.top()).ss;
q.pop();
if(!vis1[Y]) {
V[x].push_back({d+1, Y});
vis1[Y] = true;
}
ind[y]++;
while(ind[y] < SZ(V[y]) and vis1[V[y][ind[y]].ss]) {
ind[y]++;
}
if(ind[y] == SZ(V[y])) continue;
q.push({V[y][ind[y]], y});
}
V[x].push_back({0, x});
for(auto [i, j] : V[x]) {
vis1[j] = false;
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
k = sqrt(n) + 5;
for(int i = 1; i <= m; i++) {
int u1, u2;
cin >> u1 >> u2;
v[u2].push_back(u1);
}
vis.assign(n+1, 0);
for(int i = 1; i <= n; i++) {
f(i);
}
vector <int> a;
vis.assign(n+1, true);
while(q--) {
int t, y;
cin >> t >> y;
a.resize(y);
for(int i = 0; i < y; i++) {
cin >> a[i];
}
for(auto i : a) {
vis[i] = false;
}
if(y > k) {
ds.assign(n+1, -(1e9 + 1));
dfs(t);
cout << (ds[t] < 0 ? -1 : ds[t]) << '\n';
for(auto i : a) {
vis[i] = true;
}
continue;
}
int ans = -1;
for(auto [i, j] : V[t]) {
if(vis[j]) {
ans = i;
break;
}
}
cout << ans << '\n';
for(auto i : a) {
vis[i] = true;
}
}
return 0;
}
