#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define eb emplace_back
#define pu push
#define ins insert
#define fi first
#define se second
#define all(a) a.begin(),a.end()
#define bruh ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fu(x,a,b) for (auto x=a;x<=b;x++)
#define fd(x,a,b) for (auto x=a;x>=b;x--)
#define int ll
using namespace std;
//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());
/*
Competitive Programming notes that I need to study & fix my dumbass self:
1. Coding:
- Always be sure to check the memory of arrays (maybe use vectors), for loops
- Always try to maximize the memory if possible, even if you are going for subtasks
- Do not exploit #define int long long, it will kill you
2. Stress:
- Always try generating big testcases and try if they run
3. Time management:
- Don't overcommit or undercommit, always spend a certain amount of time to think a problem, don't just look at it and say I'm fucked
- Do not spend too much time coding brute-force solutions, they should be easily-codable solutions that don't take up too much time
Time management schedule:
Offline / LAH days (4 problems - 3h):
15' thinking of solution / idea
1. no idea: skip
2. yes idea: continue thinking for <= 15'
+ implementing: <= 20'
+ brute-force: <= 5'
+ test generator: <= 5'
I hate offline because I am dumb
*/
typedef pair<int, int> ii;
const int N = 2e5+5;
const int block = 100;
const int mod = 1e9+7;
const int inf = 1e18;
using cd = complex<double>;
const long double PI = acos(-1);
int power(int a,int b) {ll x = 1;if (a >= mod) a%=mod; while (b) {if (b & 1) x = x*a % mod;a = a*a % mod;b>>=1;}return x;}
int n,m,q;
vector<int> adj[N];
vector<ii> a[N];
int id[N], c[N];
bool check[N];
int dp[N];
bool vis[N];
void solve()
{
cin>>n>>m>>q;
for (int i = 1; i <= m; i++)
{
int u,v; cin>>u>>v;
adj[v].pb(u);
}
for (int i = 1; i <= n; i++)
{
priority_queue<ii> pq;
for (auto v : adj[i]) pq.push({a[v][0].fi, v});
while (!pq.empty() && a[i].size() < block)
{
int dist = pq.top().fi, v = pq.top().se;
pq.pop();
if (!vis[a[v][id[v]].se]) a[i].pb({dist+1, a[v][id[v]].se}), vis[a[v][id[v]].se] = 1;
id[v]++;
if (id[v] < a[v].size()) pq.push({a[v][id[v]].fi, v});
}
if (a[i].size() < block) a[i].pb({0, i});
for (auto v : adj[i]) id[v] = 0;
for (auto v : a[i]) vis[v.se] = 0;
}
while (q--)
{
int t, k;
cin>>t>>k;
for (int i = 0; i < k; i++) cin>>c[i], check[c[i]] = 1;
bool has = 0;
for (auto i : a[t])
{
if (!check[i.se])
{
cout<<i.fi<<endl;
has = 1;
break;
}
}
if (!has)
{
for (int i = 1; i <= n; i++) dp[i] = -1;
for (int i = 1; i <= t; i++) if (!check[i]) dp[i] = 0;
for (int i = 1; i <= t; i++)
{
for (auto j : adj[i]) if (dp[j] != -1) dp[i] = max(dp[i], dp[j]+1);
}
cout<<dp[t]<<endl;
}
for (int i = 0; i < k; i++) check[c[i]] = 0;
}
}
/*
Go through the mistakes you usually make and revise your code, for god's sake...
*/
signed main()
{
bruh
//freopen("input.inp","r",stdin);
//freopen("output.inp","w",stdout);
int t = 1;
// cin>>t;
while (t--)
{
solve();
cout<<"\n";
}
}
