#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define X first
#define Y second
#define endl '\n'
const int MAXN = 2e5 + 10;
const ll MOD = 1e9 + 7;
const ll INF = 2e18;
const int LOG = 22;
const int SQ = 200;
int n , m , q , flag[MAXN] , dp2[MAXN];
vector<int> adj[MAXN] , radj[MAXN];
vector<pii> dp[MAXN];
int main(){
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
for(int i = 0; i < m; i++){
int v , u;
cin >> v >> u;
adj[v].push_back(u);
radj[u].push_back(v);
}
for(int i = 1; i <= n; i++){
vector<pii> vec;
vec.push_back({-1 , i});
for(int u : radj[i]){
merge(vec.begin() , vec.end() , dp[u].begin() , dp[u].end() , back_inserter(dp[i]));
vec.clear();
int cnt = 0;
for(int j = dp[i].size() - 1; j >= 0; j--){
if(cnt > SQ){
break;
}
if(flag[dp[i][j].Y] == 0){
vec.push_back({dp[i][j].X , dp[i][j].Y});
flag[dp[i][j].Y] = 1;
cnt++;
}
}
dp[i].clear();
for(auto j : vec){
flag[j.Y] = 0;
}
reverse(vec.begin() , vec.end());
}
dp[i] = vec;
for(int j = 0; j < dp[i].size(); j++){
dp[i][j].X++;
}
}
while(q--){
int v , k;
cin >> v >> k;
vector<int> vec;
for(int i = 0; i < k; i++){
int u;
cin >> u;
flag[u] = 1;
vec.push_back(u);
}
if(k >= SQ){
dp2[v] = 0;
for(int i = v - 1; i >= 1; i--){
dp2[i] = -MOD;
for(int j : adj[i]){
if(j <= v){
dp2[i] = max(dp2[i] , dp2[j] + 1);
}
}
}
int mx = -1;
for(int i = 1; i <= v; i++){
if(flag[i] == 0){
mx = max(mx , dp2[i]);
}
}
cout << mx << endl;
for(int i : vec){
flag[i] = 0;
}
continue;
}
int ans = -1;
for(int j = dp[v].size() - 1; j >= 0; j--){
if(flag[dp[v][j].Y] == 0){
ans = dp[v][j].X;
break;
}
}
for(int i : vec){
flag[i] = 0;
}
cout << ans << endl;
}
return 0;
}
