/* In the name of God, aka Allah */
// let this be mytemp.cpp
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int inf = 1e9 + 50;
const int N = 1e5 + 50, SQ = 315;
int n, m, q, pd[N];
bool mark[N];
pii dp[N][SQ], tmp[SQ];
vector<int> adj[N];
void push(int u, int v) {
int p1 = 0, p2 = 0;
for (int i = 0; i < SQ; i++) {
if (p1 < SQ && (p2 >= SQ || (p2 < SQ && dp[v][p1].F > dp[u][p2].F))) tmp[i] = dp[v][p1++];
else tmp[i] = dp[u][p2++], tmp[i].F++;
}
for (int i = 0; i < SQ; i++) {
dp[v][i] = tmp[i];
}
}
void solve() {
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
}
for (int u = 1; u <= n; u++) {
dp[u][0] = {0, u};
for (int i = 1; i < SQ; i++) {
dp[u][i] = {-inf, 0};
}
}
for (int u = 1; u <= n; u++) {
for (int v:adj[u]) {
push(u, v);
}
}
vector<int> vc;
while (q--) {
int x, s;
cin >> x >> s;
vc.clear();
int ans = 0;
for (int i = 1; i <= s; i++) {
int v;
cin >> v;
vc.push_back(v);
}
if (s < SQ) {
for (int u:vc) mark[u] = 1;
for (int i = 0; i < SQ; i++) {
if (mark[dp[x][i].S]) continue;
ans = dp[x][i].F;
break;
}
for (int v:vc) mark[v] = 0;
}
else {
for (int u = 1; u <= n; u++) pd[u] = 0;
for (int u:vc) pd[u] = -1;
for (int u = 1; u <= n; u++) {
for (int v:adj[u]) {
pd[v] = max(pd[v], pd[u]+1);
}
}
ans = pd[x];
}
cout << (ans < 0? -1 : ans) << endl;
}
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
