#include <iostream>
#include <algorithm>
#include <string>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <iomanip>
#include <cassert>
#include <cstring>
#include <sstream>
#include <numeric>
#include <cstdio>
#include <bitset>
#include <math.h>
#include <assert.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
const ll MAXN = 2e5 + 10;
const ll MOD = 1e9 + 7;
const ll INF = 1e18;
const ll SQ = 320;
#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define pb push_back
#define F first
#define S second
#define Sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define cl clear()
#define endll '\n'
vector<int> adj[MAXN], adj2[MAXN];
vector<pii> vec[MAXN];
vector<pii> tmp;
vector<int> busy;
bool mark[MAXN];
int dp[MAXN];
int main(){
fast_io;
int n, m, q;
cin >> n >> m >> q;
for (int i = 0; i < m; i++){
int v, u;
cin >> v >> u;
adj[v].pb(u);
adj2[u].pb(v);
}
for (int v = 1; v <= n; v++){
vec[v].pb({0, v});
for (auto u : adj2[v]){
tmp.cl;
int p1 = 0, p2 = 0;
while(p1 < Sz(vec[u]) || p2 < Sz(vec[v])){
if (p1 < Sz(vec[u]) && mark[vec[u][p1].S]){
p1++;
continue;
}
if (p2 < Sz(vec[v]) && mark[vec[v][p2].S]){
p2++;
continue;
}
if (p1 >= Sz(vec[u])) tmp.pb(vec[v][p2]), mark[vec[v][p2].S] = 1, p2++;
else if (p2 >= Sz(vec[v])) tmp.pb({vec[u][p1].F + 1, vec[u][p1].S}), mark[vec[u][p1].S] = 1, p1++;
else if (vec[u][p1].F + 1 >= vec[v][p2].F) tmp.pb({vec[u][p1].F + 1, vec[u][p1].S}), mark[vec[u][p1].S] = 1, p1++;
else tmp.pb(vec[v][p2]), mark[vec[v][p2].S] = 1, p2++;
}
vec[v].cl;
for (auto i : tmp) mark[i.S] = 0;
while(Sz(tmp) > SQ) tmp.pop_back();
for (auto i : tmp) vec[v].pb(i);
}
}
while(q--){
int t, y;
cin >> t >> y;
if (y < SQ){
for (int i = 0; i < y; i++){
int v;
cin >> v;
mark[v] = 1;
busy.pb(v);
}
int ans = -1;
for (auto u : vec[t]){
if (!mark[u.S]){
ans = max(ans, u.F);
}
}
cout << ans << endll;
for (auto i : busy) mark[i] = 0;
busy.cl;
}
else{
for (int i = 0; i <= n; i++) dp[i] = -1000000000, mark[i] = 0;
for (int i = 0; i < y; i++){
int v;
cin >> v;
mark[v] = 1;
}
int ans = -1;
dp[t] = 0;
for (int v = t; v >= 1; v--){
for (auto u : adj[v]){
dp[v] = max(dp[v], dp[u] + 1);
}
if (mark[v] != 1) ans = max(ans, dp[v]);
}
cout << ans << endll;
for (int i = 0; i <= n; i++) mark[i] = 0;
}
}
}
