#include<bits/stdc++.h>
#include<fstream>
using namespace std;
ifstream fin("WINTER.inp");
ofstream fout("WINTER.out");
#define ll long long
#define int long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const ld PI = 3.14159265359;
const ll mod = 1e9 + 7;
const int mxn = 1e5, mxm = 2e5;
const int sq = 301;
pii dp[mxn + 1][sq + 1];
int dp2[mxn + 1], x[mxn + 1];
vt<int>adj[mxn + 1];
bool no[mxn + 1];
int n, m, q;
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
forr(i, 0, m){
int u, v; cin >> u >> v;
adj[v].pb(u);
}
for(int i = 1; i <= n; i++){
for(int j = 0; j < sq; j++){
dp[i][j] = make_pair(-1, -1);
}
}
dp[1][0] = make_pair(0, 1);
for(int i = 2; i <= n; i++){
for(auto j: adj[i]){
vt<pii>v(sq + 1);
int l = 0, r = 0;
for(int k = 0; k < sq;){
if(dp[j][r].first == -1){
if(dp[i][l].se != -1 && x[dp[i][l].se]){
l++; continue;
}
if(dp[i][l].se != -1)x[dp[i][l].se] = 1;
v[k] = dp[i][l];
l++; k++;
}
else if(dp[i][l].first > dp[j][r].first + 1){
if(dp[i][l].se != -1 && x[dp[i][l].se]){
l++; continue;
}
if(dp[i][l].se != -1)x[dp[i][l].se] = 1;
v[k] = dp[i][l];
l++; k++;
}else{
if(dp[j][r].se != -1 && x[dp[j][r].se]){
r++; continue;
}
if(dp[j][r].se != -1)x[dp[j][r].se] = 1;
v[k] = make_pair(dp[j][r].first + 1, dp[j][r].se);
r++; k++;
}
}
for(int k = 0; k < sq; k++){
dp[i][k] = v[k];
if(v[k].se != -1)x[v[k].se] = 0;
}
}
for(int j = 0; j < sq; j++){
if(dp[i][j].first == -1){
dp[i][j] = make_pair(0, i);
break;
}
}
}
forr(i, 0, q){
int t, y; cin >> t >> y;
forr(j, 0, y){
cin >> x[j]; no[x[j]] = 1;
}
if(y < sq - 3){
int ans = -1;
bool ok =0;
for(int j = 0; j < sq; j++){
if(dp[t][j].second == -1 || !no[dp[t][j].second]){
ans = dp[t][j].first; break;
}
}
cout << ans << "\n";
}else{
forr(j, 1, t + 1)dp2[j] = -1;
for(int j = 1; j <= t; j++){
if(!no[j])dp2[j] = 0;
for(auto k: adj[j]){
if(dp2[k] != -1){
dp2[j] = max(dp2[j], dp2[k] + 1);
}
}
}
cout << dp2[t] << "\n";
}
forr(j, 0, y)no[x[j]] = 0;
}
return(0);
}
