//#pragma GCC optomize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse4.1,sse4.2")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define max_heap priority_queue<pair <ll, pair <ll, ll>>>
#define min_heap priority_queue<pair <ll, ll>, vector<pair <ll, ll>>, greater<pair <ll, ll>>>
//#define min_heap priority_queue<ll, vector<ll>, greater<ll>>
#define sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define filE freopen("in.txt", "r", stdin); freopen("out1.txt", "w", stdout);
#define endl '\n'
#define md(a) (a % mod + mod) % mod
#define pb push_back
//cout << vectorprecision(5) << fixed << f;
//hash prime = 769
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll const maxn = 1e5 + 123;
ll const inf = 2e18;
ll const loG = 23;
ll const mod = 1e9 + 7;
//ll const mod = 998244353;
ll const sq = 400;
ll power(ll a, ll b, ll mod){if(b==0)return 1;if(b==1)return a;ll x = power(a, b / 2, mod);return (((x * x) % mod) * (b % 2 ? a : 1)) % mod;}
int n, m, q, mx[maxn], dp[maxn];
vector <int> g[maxn];
vector <pair <int, int>> tool[maxn];
bool mark[maxn];
void Solve(){
cin >> n >> m >> q;
for (int i = 1; i < m + 1; i++){
int a, b; cin >> a >> b;
g[b].pb(a);
}
tool[1].pb({0, 1});
for (int i = 1; i < n + 1; i++)
mx[i] = -mod;
for (int i = 2; i < n + 1; i++){
vector <int> tmp; tmp.clear();
for (int u : g[i]){
for (auto p : tool[u]){
mx[p.second] = max(mx[p.second], p.first + 1);
if (!mark[p.second]){
tmp.pb(p.second);
mark[p.second] = 1;
}
}
}
vector <pair <int, int>> st; st.clear();
for (int x : tmp){
st.pb({mx[x], x});
mark[x] = 0;
mx[x] = -mod;
}
st.pb({0, i});
//cout << i << ' ' << st.size() << endl;
sort(st.begin(), st.end());
int cnt = 0;
for (int j = st.size() - 1; (j > -1 && cnt <= sq); j--){
cnt++;
tool[i].pb({st[j].first, st[j].second});
}
}
// for (int i = 2; i < n + 1; i++){
// cout << i << " :: " << endl;
// for (auto p : tool[i])
// cout << p.first << ' ' << p.second << endl;
// }
while (q--){
int v, t; cin >> v >> t;
vector <int> tmp; tmp.clear();
for (int i = 1; i < t + 1; i++){
int x; cin >> x;
tmp.pb(x);
mark[x] = 1;
}
if (t >= sq){
for (int i = 1; i < v + 1; i++){
dp[i] = -mod;
if (!mark[i])
dp[i] = 0;
for (int u : g[i])
dp[i] = max(dp[i], dp[u] + 1);
}
cout << (dp[v] < 0 ? -1 : dp[v]) << endl;
}
else{
int ans = -mod;
for (auto p : tool[v]){
if (!mark[p.second])
ans = max(ans, p.first);
}
cout << (ans < 0 ? -1 : ans) << endl;
}
for (int x : tmp)
mark[x] = 0;
}
}
int main(){
sariE;// filE;
int test = 1;
//cin >> test;
while (test--) Solve();
return 0;
}
