#include <bits/stdc++.h>
#define endl '\n'
#define SZ(x) ((int)x.size())
#define pb push_back
using namespace std;
template<class T, class T2> inline void chkmax(T &x, const T2 &y) { if(x < y) x = y; }
template<class T, class T2> inline void chkmin(T &x, const T2 &y) { if(x > y) x = y; }
const int MAXN = (int)1e5 + 17 + 42;
const int B = 200;
int n, m, q;
vector<int> adj[MAXN];
void read()
{
cin >> n >> m >> q;
for(int i = 0; i < m; i++)
{
int u, v;
cin >> u >> v;
adj[v].push_back(u);
}
}
bool ok[MAXN];
int _dp[MAXN];
int Tm_vis[MAXN], cnt_t;
int TMS = 0;
vector<pair<int, int> > dp[MAXN];
int rec(int u)
{
if(Tm_vis[u] >= cnt_t) return _dp[u];
Tm_vis[u] = cnt_t;
if(ok[u]) _dp[u] = 0;
else _dp[u] = -1e9;
for(int v: adj[u])
chkmax(_dp[u], rec(v) + 1);
return _dp[u];
}
int solve_brute(int u, vector<int> blocked)
{
for(int x: blocked) ok[x] = 0;
cnt_t++;
int ans = rec(u);
for(int x: blocked) ok[x] = 1;
return ans < 0 ? -1 : ans;
}
bool same[MAXN];
bool cmp(pair<int, int> a, pair<int, int> b) { return a.second > b.second; }
int USED[MAXN];
vector<pair<int, int> > merge(vector<pair<int, int> > a, vector<pair<int, int> > b)
{
for(auto &it: b) it.second++;
int po_b = 0;
vector<pair<int, int> > ret;
for(auto it: a)
{
while(po_b < SZ(b) && b[po_b].second > it.second)
{
if(USED[b[po_b].first] != -1) { po_b++; continue; }
else
{
USED[b[po_b].first] = 1;
ret.pb(b[po_b]);
po_b++;
}
}
if(USED[it.first] != -1) continue;
USED[it.first] = 1;
ret.pb(it);
}
while(po_b < SZ(b))
{
if(USED[b[po_b].first] != -1) { po_b++; continue; }
else
{
USED[b[po_b].first] = 1;
ret.pb(b[po_b]);
po_b++;
}
}
for(auto it: ret) USED[it.first] = -1;
while(SZ(ret) > B) ret.pop_back();
return ret;
}
void solve()
{
memset(USED, -1, sizeof(USED));
for(int i = 1; i <= n; i++) ok[i] = 1;
for(int u = 1; u <= n; u++)
{
dp[u].push_back({u, 0});
for(auto v: adj[u])
dp[u] = merge(dp[u], dp[v]);
}
while(q--)
{
int st, sz;
vector<int> li;
cin >> st >> sz;
for(int i = 0; i < sz; i++)
{
int x;
cin >> x;
li.push_back(x);
}
vector<int> initial_li = li;
if(li.size() >= B)
{
cout << solve_brute(st, li) << endl;
continue;
}
for(auto it: li) same[it] = 1;
int answer = 0;
for(auto it: dp[st])
if(!same[it.first])
chkmax(answer, it.second);
for(auto it: li) same[it] = 0;
if(answer < 0) answer = -1;
if(answer == 0)
{
for(auto it: initial_li)
if(it == st) answer = -1;
}
cout << answer << endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
read();
solve();
return 0;
}
