#include <bits/stdc++.h>
// #pragma GCC optimize(3)
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define F first
#define S second
#define endl '\n'
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
using namespace std;
using ll = long long;
using i128 = __int128;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const ll Inf = 1e18;
const int inf = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const int N = 2e5 + 5;
void solve(){
int n, m, q; cin >> n >> m >> q;
vector<vector<int>> g(n+1);
for(int i=1; i<=m; i++){
int x, y; cin >> x >> y;
g[x].push_back(y);
}
const int B = 80;
vector<vector<pii>> path(n+1);
auto rs = [&](auto &q) -> void {
sort(q.rbegin(), q.rend());
while(q.size() > B) q.pop_back();
return;
};
for(int i=1; i<=n; i++){
path[i].push_back({0, i});
rs(path[i]);
for(auto j : g[i]){
for(auto [x, y] : path[i]){
path[j].push_back({x + 1, y});
}
}
}
vector<bool> ban(n+1);
for(int i=1; i<=q; i++){
int pos; cin >> pos;
int k; cin >> k;
vector<int> t(k);
for(int j=0; j<k; j++) cin >> t[j];
for(auto x : t) ban[x] = 1;
if(k < B){
int res = -1;
for(auto [x, y] : path[pos]){
if(ban[y]) continue;
res = x;
break;
}
cout << res << endl;
}
else{
vector<int> dp(n+1, -1);
dp[pos] = 0;
for(int i=pos; i>=1; i--){
int ma = 0;
for(auto j : g[i]){
if(dp[j] == -1) continue;
ma = max(ma, dp[j]);
}
dp[i] = ma + 1;
}
int res = -1;
for(int i=1; i<=pos; i++){
if(ban[i]) continue;
res = max(res, dp[i]);
}
cout << res << endl;
}
for(auto x : t) ban[x] = 0;
}
}
int main(){
ios::sync_with_stdio(0); cin.tie(0);
//freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
int t = 1;
//cin >> t;
while(t--)
solve();
return 0;
}
