//Dost SEFEROĞLU
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define vi vector<int>
#define all(xx) xx.begin(),xx.end()
#define ps(xxx) cout << (xxx) << endl;
const int N = 1e5+1,inf = 1e18,MOD = 998244353,B = 350;
vi edges[N],egdes[N];
vector<pii> mfs[N];
vi vis(N,0);
vi best(N);
void bfs(int root) {
queue<int> q;
q.push(root);
while (!q.empty()) {
int node = q.front();
q.pop();
vis[node] = 1;
vector<pii> ps;
vi allnbs;
for (auto it : egdes[node]) {
for (auto itt : mfs[it]) {
if (!best[itt.ss]) allnbs.push_back(itt.ss);
best[itt.ss] = max(best[itt.ss],itt.ff+1);
}
}
for (auto it : allnbs) ps.push_back({best[it],it});
if (!ps.empty()) sort(all(ps),greater<pii>());
if (ps.size() > B+5) ps.resize(B+5);
swap(mfs[node],ps);
mfs[node].push_back({0,node});
for (auto it : egdes[node]) for (auto itt : mfs[it]) best[itt.ss] = 0;
for (auto it : edges[node]) if (!vis[it]) q.push(it);
}
}
vector<pii> vv;
vi mxdist(N);
void bfs2(int root) {
queue<int> q;
q.push(root);
mxdist[root] = 0;
vis[root] = 1;
while (!q.empty()) {
int f = q.front();
q.pop();
vis[f] = 1;
if (f != root) mxdist[f] = -1;
for (auto it : edges[f]) if(mxdist[it]!=-1) mxdist[f] = max(mxdist[f],mxdist[it]+1);
for (auto it : egdes[f]) if (!vis[it]) q.push(it);
}
}
void solve() {
int n,m,q;
cin >> n >> m >> q;
for (int i=1;i<=m;i++) {
int a,b;
cin >> a >> b;
edges[a].push_back(b);
egdes[b].push_back(a);
}
for (int i=1;i<=n;i++) {
if (egdes[i].size()) continue;
bfs(i);
}
vi banned(n+1,0);
while (q--) {
int node,k;
cin >> node >> k;
vi c(k+1);
for (int i=1;i<=k;i++) cin >> c[i];
for (int i=1;i<=k;i++) banned[c[i]] = 1;
if (k <= B) {
bool fl = 0;
for (auto it : mfs[node]) {
if (!banned[it.ss]) {
fl = 1;
cout << it.ff << endl;
break;
}
}
if (!fl) cout << -1 << endl;
}
else {
vis.assign(n+1,0);
mxdist.assign(n+1,-1);
bfs2(node);
int ans = -1;
for (auto it : vv) {
if (!banned[it.ff]) ans= max(ans,it.ss);
}
vv.clear();
cout << ans << '\n';
}
for (int i=1;i<=k;i++) banned[c[i]] = 0;
}
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
