#include <bits/stdc++.h>
using namespace std;
#define ll unsigned long long
#define pii pair<int,int>
#define fr first
#define sc second
#define pow2(i) (1<<i)
#define eb emplace_back
#define mp make_pair
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define FOR(_i, _s, _n) for (int _i = _s; _i <= _n; ++_i)
#define FOD(_i, _s, _n) for (int _i = _s; _i >= _n; --_i)
#define firstbit(_mask) __builtin_ctz(_mask)
#define lastbit(_mask) __builtin_clz(_mask)
#define countbit(_mask) __builtin_popcount(_mask)
int getbit(int mask, int i) {
return (mask >> i) & 1;
}
void flipbit(int &mask, int i) {
mask ^= (1 << i);
}
void setbit(int &mask, int i) {
mask |= (1 << i);
}
template <typename T> inline void read(T &x) {
x = 0; char c;
while (!isdigit(c = getchar()));
do x = x*10 + c - '0';
while (isdigit(c = getchar()));
}
template <typename T> inline void write(T x) {
if (x > 9) write(x/10);
putchar(x % 10 + 48);
}
const int dd[4]={-1, 0, 1, 0}, dc[4]={0, 1, 0, -1};
//#define PROBLEMS "bitaro"
#ifdef PROBLEMS
#define cin fi
#define cout fo
ifstream fi (PROBLEMS".inp");
ofstream fo (PROBLEMS".out");
#endif
#define camnguyenmeow ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
/* /\_/\
(= ._.)
/ >? \>$
*/
bool cantgo[100005];
int mx[100005], d[100005], maxx = 200;
vector<int> a[100005];
vector<pii> dt[100005];
pii b[100005];
int main()
{
camnguyenmeow
int n, m, q, u, v, cnt;
cin >> n >> m >> q;
while (m--) {
cin >> u >> v;
a[v].push_back(u);
}
FOR(i, 1, n) {
cnt = 0;
vector<int> change;
for (int v : a[i]) {
if (!mx[v]) change.push_back(v);
mx[v] = max(mx[v], 1);
for (pii it : dt[v]) {
if (!mx[it.sc]) change.push_back(it.sc);
mx[it.sc] = max(mx[it.sc], it.fr + 1);
}
}
cnt = 0;
for (int v : change) {
b[++cnt] = {mx[v], v};
mx[v] = 0;
}
nth_element(b + 1, b + 1 + min(maxx, cnt), b + 1 + cnt, [&](const pii &A, const pii &B) {
return A.fr > B.fr;
});
dt[i].assign(min(cnt, maxx), {0, 0});
FOR(j, 0, min(cnt, maxx) - 1)
dt[i][j] = b[j + 1];
}
while (q--) {
int t, y;
cin >> t >> y;
vector<int> haha(y);
for (int &i : haha) {
cin >> i; cantgo[i] = 1;
}
if (y >= maxx) {
FOR(i, 1, t) {
d[i] = 0;
for (int j : a[i])
if (!cantgo[j] || d[j])
d[i] = max(d[i], d[j] + 1);
}
if (cantgo[t] && d[t] == 0) cout << -1 <<'\n';
else cout << d[t] <<'\n';
}
else {
int ans = -1;
for (pii i : dt[t])
if (!cantgo[i.sc]) ans = max(ans, i.fr);
if (!cantgo[t]) ans = max(ans, 0);
cout << ans << '\n';
}
for (int i : haha) cantgo[i] = 0;
}
return 0;
}
