#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
#define f first
#define s second
#define pb push_back
#define pf push_front
#define mpp make_pair
#define sz(x) (int)x.size()
//#define int ll
const int N = 1e5+10, X = 317;
int n, m, q;
set<pii> st[N];
int dp[N];
vi g[N];
void caldp() {
for(int i = 1; i <= n; i++) {
map<int, int> mp;
for(int j : g[i]) {
for(auto it = st[j].begin(); it != st[j].end(); it++) {
pii e = *it;
int x = e.s, w = e.f+1;
if(w > mp[x]) {
st[i].erase(mpp(mp[x], x));
mp[x] = w;
st[i].insert(mpp(mp[x], x));
}
while(sz(st[i]) > X)
st[i].erase(st[i].begin());
}
if(1 > mp[j]) {
st[i].erase(mpp(mp[j], j));
mp[j] = 1;
st[i].insert(mpp(mp[j], j));
}
while(sz(st[i]) > X)
st[i].erase(st[i].begin());
}
}
}
int32_t main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
for(int i = 0; i < m; i++) {
int v, u;
cin >> v >> u;
g[u].pb(v);
}
caldp();
while(q--) {
int t, y;
cin >> t >> y;
if(y < X) {
set<int> hld;
for(int i = 0; i < y; i++) {
int x; cin >> x;
hld.insert(x);
}
int flag = 0;
for(auto it = st[t].rbegin(); !flag && it != st[t].rend(); it++) {
pii e = *it;
if(!hld.count(e.s))
flag = e.f;
}
if(!flag) {
if(hld.count(t))
cout << -1 << endl;
else
cout << 0 << endl;
}
else
cout << flag << endl;
}
else {
for(int i = 0; i < y; i++) {
int x; cin >> x;
dp[x] = -1;
}
for(int i = 1; i <= t; i++) {
dp[i] = 0;
for(int j :g[i])
if(dp[j] != -1)
dp[i] = max(dp[i], dp[j]+1);
}
cout << dp[t] << endl;
}
}
}
