#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ll long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"
const int MOD = 1e9+7;
const int inf = 1e9;
const ll linf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// -------------------------------------------------- Main Code --------------------------------------------------
const int N = 1e5+5, SQRT = 450;
vi g[N];
vector<pair<int, int>> dp[N];
int blocked[N];
void sol() {
int n, m, q; cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int a, b; cin >> a >> b;
g[b].pb(a);
}
dp[1].pb({0, 1});
for (int i = 2; i <= n; i++) {
dp[i].pb({0, i});
for (auto ch : g[i]) {
for (auto x : dp[ch]) {x.f++; dp[i].pb(x);}
}
sort(all(dp[i])); reverse(all(dp[i]));
while (dp[i].size() > SQRT) dp[i].pop_back();
}
while (q--) {
int city, y; cin >> city >> y;
vi cities;
for (int i = 0; i < y; i++) {int x; cin >> x; cities.pb(x); blocked[x] = 1;}
if (y >= SQRT) {
vi dpp(n+1);
for (int i = 1; i <= city; i++) {
dpp[i] = (blocked[i]?-inf:0);
for (auto ch : g[i]) {
dpp[i] = max(dpp[i], 1+dpp[ch]);
}
}
cout << (dpp[city]<0?-1:dpp[city]) << endl;
}
else {
int ans = -1;
for (auto &i : dp[city]) {
if (!blocked[i.s]) {ans = i.f; break;}
}
cout << ans << endl;
}
// reset blocked array
for (auto &i : cities) blocked[i] = 0;
}
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
