#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
using namespace std;
const int mxN = 3e5 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
if (a < b) {a = b; return true;} return false;
}
vector<int> topo;
vector<int> adj[mxN];
vector<int> radj[mxN];
bool vis[mxN];
bool isremove[mxN];
int dp[mxN];
void dfs(int u)
{
vis[u] = true;
for(int v : adj[u]) {
if(!vis[v]) dfs(v);
}
topo.pb(u);
}
void solve()
{
int n , m , q;
cin >> n >> m >> q;
for(int i = 1 ; i <= m ; i++) {
int u , v;
cin >> u >> v;
adj[u].pb(v);
radj[v].pb(u);
}
for(int i = 1 ; i <= n ; i++) if(!vis[i]) dfs(i);
reverse(all(topo));
// for(int i : topo) cout << i << ' ';
// cout << endl;
while(q--) {
int pos , x;
cin >> pos >> x;
vector<int> remove;
for(int i = 1 ; i <= x ; i++) {
int y;
cin >> y;
isremove[y] = true;
remove.pb(y);
}
for(int i = 1 ; i <= n ; i++) dp[i] = -inf;
for(int i : topo) {
if(isremove[i] == false) dp[i] = 0;
for(int j : radj[i]) {
maximize(dp[i] , dp[j] + 1);
}
}
for(int i : remove) isremove[i] = false;
if(dp[pos] < 0) cout << -1 << endl;
else cout << dp[pos] << endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
//freopen(TASK".in" , "r" , stdin);
//freopen(TASK".out" , "w" , stdout);
int tc = 1;
//cin >> tc;
while(tc--) {
solve();
}
return 0;
}
