// khodaya khodet komak kon
# include <bits/stdc++.h>
/*
// ordered_set
# include <ext/pb_ds/assoc_container.hpp>
# include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
# define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
*/
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <pii, int> ppi;
typedef pair <int, pii> pip;
typedef pair <pii, pii> ppp;
typedef pair <ll, ll> pll;
# define A first
# define B second
# define endl '\n'
# define sep ' '
# define all(x) x.begin(), x.end()
# define kill(x) return cout << x << endl, 0
# define SZ(x) int(x.size())
# define lc id << 1
# define rc id << 1 | 1
# define InTheNameOfGod ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
ll power(ll a, ll b, ll md) {return (!b ? 1 : (b & 1 ? a * power(a * a % md, b / 2, md) % md : power(a * a % md, b / 2, md) % md));}
const int xn = 2e5 + 10;
const int xm = - 20 + 10;
const int sq = 450;
const int inf = 1e9 + 10;
const ll INF = 1e18 + 10;
const int mod = 998244353;
const int base = 257;
int n, m, q, ptr[xn], dp[xn], ans[xn];
pii a[xn][sq], b[sq];
vector <int> adj[2][xn], vec[xn], query[xn];
bool mark[xn];
void solve(int id, int s){
memset(dp, - 1, sizeof dp);
for (int v : vec[id])
mark[v] = true;
dp[s] = 0;
for (int v = s; v >= 1; -- v){
for (int u : adj[0][v])
if (dp[u] != - 1)
dp[v] = max(dp[v], dp[u] + 1);
if (!mark[v])
ans[id] = max(ans[id], dp[v]);
}
for (int v : vec[id])
mark[v] = false;
}
void merge(int v, int u){
int pt1 = 0, pt2 = 0, pt3 = 0;
while (pt1 < ptr[v] || pt2 < ptr[u]){
if (pt3 == sq)
break;
if (pt1 < ptr[v] && mark[a[v][pt1].A]){
++ pt1;
continue;
}
if (pt2 < ptr[u] && mark[a[u][pt2].A]){
++ pt2;
continue;
}
if (pt2 == ptr[u] || (pt1 < ptr[v] && a[v][pt1].B >= a[u][pt2].B))
b[pt3 ++] = {a[v][pt1].A, a[v][pt1 ++].B + 1};
else
b[pt3 ++] = a[u][pt2 ++];
mark[b[pt3 - 1].A] = true;
}
ptr[u] = pt3;
for (int i = 0; i < pt3; ++ i)
a[u][i] = b[i], mark[b[i].A] = false;
}
int main(){
InTheNameOfGod;
cin >> n >> m >> q;
while (m --){
int v, u;
cin >> v >> u;
adj[0][v].push_back(u);
adj[1][u].push_back(v);
}
for (int i = 1; i <= q; ++ i){
int s, sz;
cin >> s >> sz;
ans[i] = - 1;
for (int j = 0; j < sz; ++ j){
int v;
cin >> v;
vec[i].push_back(v);
}
if (sz >= sq)
solve(i, s);
else
query[s].push_back(i);
}
memset(mark, false, sizeof mark);
for (int v = 1; v <= n; ++ v){
for (int u : adj[1][v])
merge(u, v);
if (ptr[v] < sq)
a[v][ptr[v] ++] = {v, 0};
for (int id : query[v]){
for (int u : vec[id])
mark[u] = true;
for (int i = ptr[v] - 1; i >= 0; -- i)
if (!mark[a[v][i].A])
ans[id] = a[v][i].B;
for (int u : vec[id])
mark[u] = false;
}
}
for (int i = 1; i <= q; ++ i)
cout << ans[i] << endl;
return 0;
}
