#include <bits/stdc++.h>
// #include <ext/rope>
// #include <ext/pb_ds/assoc_container.hpp>
// using namespace __gnu_pbds;
// using namespace __gnu_cxx;
using namespace std;
// #define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define bit(mask, i) ((mask >> i) & 1)
#define el '\n'
#define F first
#define S second
template <class X, class Y> bool maximize(X &x, const Y &y) { return (x < y ? x = y, 1 : 0); }
template <class X, class Y> bool minimize(X &x, const Y &y) { return (x > y ? x = y, 1 : 0); }
const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7;
const int MULTI = 0;
const ld eps = 1e-9;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0}; // R D L U
const int ddx[4] = {-1, 1, 1, -1}, ddy[4] = {1, 1, -1, -1}; // UR DR DL UL
const char cx[4] = {'R', 'D', 'L', 'U'};
const ll base = 31;
const int nMOD = 2;
const ll mods[] = {(ll)1e9 + 10777, (ll)1e9 + 19777, (ll)1e9 + 3, (ll)1e9 + 3777};
const int N = 1e5 + 5;
const int S = 316;
int n, m, q, r, mark[N], dist[N], del[N], dis[N];
vector<int> adj[N];
vector<pair<int, int>> lps[N];
void createLps() {
for (int i = 1; i <= n; ++i) {
vector<int> vec;
vec.push_back(i);
dist[i] = 0;
mark[i] = i;
for (int v: adj[i])
for (auto P: lps[v])
if (mark[P.S] != i) {
vec.push_back(P.S);
mark[P.S] = i;
dist[P.S] = P.F + 1;
} else
maximize(dist[P.S], P.F + 1);
for (int x: vec) lps[i].push_back(make_pair(dist[x], x));
sort(lps[i].begin(), lps[i].end(), greater<pair<int, int>>());
int len = (int) lps[i].size();
while (len > S) lps[i].pop_back(), len--;
}
}
void bfs(int id) {
fill(dis + 1, dis + 1 + n, 0);
for (int i = 1; i <= r; ++i) {
for (int u: adj[i])
maximize(dis[i], dis[u] + 1);
if (dis[i] == 0 && del[i] == id)
dis[i] = -1;
}
}
void solve() {
cin >> n >> m >> q;
for (int i = 1, u, v; i <= m; ++i) {
cin >> u >> v;
adj[v].push_back(u);
}
createLps();
for (int i = 1; i <= q; ++i) {
int y;
cin >> r >> y;
for (int j = 1, d; j <= y; ++j) {
cin >> d;
del[d] = i;
}
if (y >= S) {
bfs(i);
cout << dis[r] << el;
} else {
int res = -1;
for (auto P: lps[r])
if (del[P.S] != i) {
res = P.F;
break;
}
cout << res << el;
}
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (!MULTI) solve();
else {
int test; cin >> test;
while (test--) solve();
}
return 0;
}
