#include <bits/stdc++.h>
#define forr(_a,_b,_c) for(_a = (_b); _a <= (_c); ++_a)
#define ford(_a,_b,_c) for(_a = (_b) + 1; _a --> (_c);)
#define forf(_a,_b,_c) for(_a = (_b); _a < (_c); ++_a)
#define st first
#define nd second
#define ll long long
#define ull unsigned long long
#define pii pair <int,int>
#define pll pair <ll,ll>
#define piii pair <int,pii>
#define vi vector <int>
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define file "test"
using namespace std;
const int N = 2e5 + 5;
const ll oo = 1e9;
const ll mod = 1e9 + 7;
int pv = 100000, dp[N], w[N], u, v, k, m, n, q, i, e[N], x, mx[N];
vi a[N], tmp;
vector <pii> f[N];
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef hqm
freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
#endif
cin >> n >> m >> q;
forr (i, 1, m){
cin >> u >> v;
a[v].pb(u);
}
forr (i, 1, n){
f[i].pb({0, i});
for (int v : a[i]){
for (pii u : f[v])
tmp.pb(u.nd), mx[u.nd] = max (mx[u.nd], u.st + 1);
}
sort(all(tmp));
tmp.erase(unique(all(tmp)), tmp.end());
for (int u : tmp)
f[i].pb({u, mx[u]}), mx[u] = 0;
tmp.clear();
sort(all(f[i]), greater<pii>());
while (f[i].size() > pv)
f[i].pop_back();
}
while (q--){
cin >> x;
cin >> k;
forr (i, 1, k){
cin >> e[i];
w[e[i]] = 1;
}
int ans = -1;
if (k < pv){
for (pii u : f[x]){
//cout << u.st << " " << u.nd << "\n";
if (!w[u.nd]){
ans = u.st;
break;
}
}
}
else {
memset(dp, -0x3f, sizeof dp);
forr (i, 1, x){
if (!w[i])
dp[i] = 0;
for (int v : a[i])
dp[i] = max (dp[i], dp[v] + 1);
}
if (dp[x] >= 0)
ans = dp[x];
}
cout << ans << "\n";
forr (i, 1, k)
w[e[i]] = 0;
}
return 0;
}
/*
*/
