#include <bits/stdc++.h>
#define int long long
#define debug cout << "ok\n";
#define SQR(x) (1LL * ((x) * (x)))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pli pair<ll,int>
#define vi vector<int>
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int ui;
using namespace std;
const int M = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);
const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};
template<class _, class __>
bool minimize(_ &x, const __ y){
if(x > y){
x = y;
return true;
} else return false;
}
template<class _, class __>
bool maximize(_ &x, const __ y){
if(x < y){
x = y;
return true;
} else return false;
}
template<class _,class __>
void Add(_ &x, const __ y) {
x += y;
if (x >= M) {
x -= M;
}
return;
}
template<class _,class __>
void Diff(_ &x, const __ y) {
x -= y;
if (x < 0) {
x += M;
}
return;
}
//--------------------------------------------------------------
const int MaxN = 1e5+7;
const int S = 317;
int n,q,m,cnt,vis[MaxN],C[MaxN],f[MaxN];
vi a[MaxN];
vector<pii> lis[MaxN];
vector<pii> operator + (vector<pii> a,vector<pii> b) {
cnt++;
vector<pii> res;
int p1 = 0;
int p2 = 0;
while (res.size() < S && p1 < a.size() && p2 < b.size()) {
if (vis[a[p1].se] == cnt) p1++;
else if (vis[b[p2].se] == cnt) p2++;
else {
if (a[p1].fi < b[p2].fi) {
res.pb(b[p2]);
vis[b[p2].se] = cnt;
p2++;
}
else {
res.pb(a[p1]);
vis[a[p1].se] = cnt;
p1++;
}
}
}
while (res.size() < S && p1 < a.size()) {
if (vis[a[p1].se] == cnt) p1++;
else {
res.pb(a[p1]);
vis[a[p1].se] = cnt;
p1++;
}
}
while (res.size() < S && p2 < b.size()) {
if (vis[b[p2].se] == cnt) p2++;
else {
res.pb(b[p2]);
vis[b[p2].se] = cnt;
p2++;
}
}
return res;
}
void sol() {
cin >> n >> m >> q;
for (int i=1;i<=m;i++) {
int u,v;
cin >> u >> v;
a[v].pb(u);
}
for (int i=1;i<=n;i++) {
for (int v : a[i]) {
lis[i] = lis[i] + lis[v];
}
for (pii & x : lis[i]) x.fi++;
if (lis[i].size() < S) lis[i].pb(mp(0,i));
}
for (int i=1;i<=n;i++) vis[i] = 0;
for (int i=1;i<=q;i++) {
int T,Y;
cin >> T >> Y;
for (int j=1;j<=Y;j++) {
cin >> C[j];
vis[C[j]] = i;
}
if (Y < S) {
bool ch = true;
for (pii tmp : lis[T]) {
if (vis[tmp.se] != i) {
cout << tmp.fi << '\n';
ch = false;
break;
}
}
if (ch) cout << -1 << '\n';
}
else {
for (int j=1;j<=n;j++) {
if (vis[j] != i) {
f[j] = 0;
}
else f[j] = -INF;
for (int v : a[j]) {
maximize(f[j],f[v] + 1);
}
}
if (f[T] >= 0) cout << f[T] << '\n';
else cout << -1 << '\n';
}
}
}
signed main() {
// freopen("test.inp","r",stdin);
// freopen("test.out","w",stdout);
FAST
int t=1;
// cin >> t;
while (t--) sol();
}
