/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;
int n, m, q;
vi g[N], G[N];
vector<pii> T[N];
void solve(){
cin >> n >> m >> q;
for(int i = 1; i <= m; ++i){
int u, v; cin >> u >> v;
g[v].pb(u);
G[u].pb(v);
}
for(int i = 1; i <= n; ++i){
T[i].pb({0, i});
}
vector<bool> VIS(n+1);
vi used;
for(int i = 1; i <= n; ++i){
for(int u: g[i]){
vector<pii> P;
int ptr = 0;
for(int j = 0; j < T[i].size(); ++j){
while(ptr < T[u].size() && T[u][ptr].ff + 1 >= T[i][j].ff){
P.pb({T[u][ptr].ff + 1, T[u][ptr].ss});
++ptr;
}
P.pb(T[i][j]);
}
while(ptr < T[u].size()) {P.pb({T[u][ptr].ff + 1, T[u][ptr].ss}); ptr++;}
T[i].clear();
for(int j = 0; j < P.size() && T[i].size() <= 400; ++j){
if(VIS[P[j].ss]) continue;
T[i].pb(P[j]);
used.pb(P[j].ss);
VIS[P[j].ss] = 1;
}
for(int x: used) VIS[x] = 0;
used.clear();
}
}
vector<vi> Q(q + 1);
vector<bool> bad(n + 1);
for(int i = 1; i <= q; ++i){
int y, v; cin >> v >> y;
Q[i].resize(y);
for(int &x: Q[i]){
cin >> x;
bad[x] = 1;
}
if(y >= 395){
vi dp(n + 1, 0);
for(int x: Q[i]) dp[x] = -MOD;
for(int j = 1; j <= n; ++j){
for(int u: G[j]) dp[u] = max(dp[u], dp[j] + 1);
}
cout << (dp[v] < 0 ? -1 : dp[v]) << '\n';
}else{
int ans = -1;
for(auto [dist, x]: T[v]){
if(!bad[x]){
ans = dist;
break;
}
}
cout << ans << '\n';
}
for(int &x: Q[i]){
bad[x] = 0;
}
}
}
int main(){
cin.tie(0); ios::sync_with_stdio(0);
int tt = 1, aa;
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
while(tt--){
solve();
en;
}
cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
return 0;
}
