#include <bits/stdc++.h>
#define fi first
#define se second
#define For(i, a, b) for (int i=a;i<=b;++i)
#define Ford(i, a, b) for(int i=a;i>=b;--i)
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef array<int, 3> arr;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
const int N = 2 * 1e5 + 5;
const int B = 177;
int f[N];
int vis[N], ver = 0;
void merge(vii &a, vii &b) {
ver++;
int n = a.size(), m = b.size();
int i = 0, j = 0, s = min(n + m, B);
static ii c[N];
int k = 0;
while (k < s) {
if (i >= n || (j < m && b[j].se + 1 > a[i].se)) {
if (vis[b[j].fi] != ver) {
c[++k] = {b[j].fi, b[j].se + 1};
vis[b[j].fi] = ver;
}
j++;
}
else {
if (vis[a[i].fi] != ver) {
c[++k] = a[i];
vis[a[i].fi] = ver;
}
i++;
}
if (i >= n && j >= m) break;
}
For(i, 0, n - 1) a[i] = c[i + 1];
For(i, n + 1, k) a.push_back(c[i]);
}
void solve()
{
int n, m, q;
cin >> n >> m >> q;
vector<vi> pre(n + 5);
For(i, 1, m) {
int u, v; cin >> u >> v;
pre[v].push_back(u);
}
vector<vii> good(n + 5);
For(i, 1, n) {
good[i].push_back({i, 0});
for (int j : pre[i]) {
merge(good[i], good[j]);
}
}
while (q--) {
int u; cin >> u;
ver++;
int y; cin >> y;
int cnt = 0;
For(i, 1, y) {
int x; cin >> x;
vis[x] = ver;
}
if (y < B) {
int ans = -1;
for (ii i : good[u]) if (vis[i.fi] != ver) {
ans = i.se;
break;
}
cout << ans << "\n";
}
else {
For(i, 1, u) {
if (vis[i] == ver) {
f[i] = -1;
continue;
}
f[i] = 0;
for (int j : pre[i])
f[i] = max(f[i], f[j] + 1);
}
cout << f[u] << "\n";
}
}
}
int main()
{
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
solve();
// cerr << 1.0 * clock() / CLOCKS_PER_SEC;
return 0;
}
