/*
_ _ _ __ __ _____
/\ | | /\ | | | | | \/ |/ ____|
/ \ | |__ ___ / \ | |__ __| | ___ | \ / | |
/ /\ \ | '_ \ / _ \ / /\ \ | '_ \ / _` |/ _ \| |\/| | |
/ ____ \| |_) | (_) / ____ \| |_) | (_| | (_) | | | | |____
/_/ \_\_.__/ \___/_/ \_\_.__/ \__,_|\___/|_| |_|\_____|
*/
// build command:
// g++ -o "exe" "%f" -Wall -Wextra -pedantic -std=c++11 -O2 -Wshadow -Wformat=2 -Wfloat-equal -Wconversion -Wlogical-op -Wshift-overflow=2 -Wduplicated-cond -Wcast-qual -Wcast-align -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC -D_FORTIFY_SOURCE=2 -fsanitize=address -fsanitize=undefined -fno-sanitize-recover -fstack-protector -D LOCAL -Wno-unused-result
#include <bits/stdc++.h>
using namespace std;
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#ifdef LOCAL
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif
#define F first
#define S second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const ld eps = 1e-9;
const int mod = 1e9 + 7;
const int oo = 1e9 + 7;
const ll lloo = 1e18 + 7;
const int N = 1e5 + 7;
const int SZ = 150;
int n,m,q;
vector<int> g[N],tg[N];
vector<int> toposort;
int vis[N];
void tsort(int u) {
vis[u] = 1;
for(auto v:g[u]) {
if (!vis[v]) tsort(v);
}
toposort.pb(u);
}
vector<pii> dp[N]; // {dist[u],u}
int tmp[N];
int val[N];
bool cmp(int x,int y) {
return val[x] > val[y];
}
void solve() {
scanf("%d %d %d",&n,&m,&q);
for(int i = 0 ; i < m ; i++) {
int u,v;
scanf("%d %d",&u,&v);
g[u].pb(v);
tg[v].pb(u);
}
for(int i = 1; i <= n ; i++) if (!vis[i]) tsort(i);
reverse(all(toposort));
vector<int> ok(n+1,0);
for(auto u:toposort) {
vector<int> ptr(sz(tg[u]),0);
vector<int> alldp;
for(auto v:tg[u]) {
for(auto vvv:dp[v]) {
int vv = vvv.S;
if (ok[vv]) {
val[vv] = max(val[vv],vvv.F+1);
} else {
val[vv] = vvv.F+1;
alldp.pb(vv);
}
}
}
alldp.pb(u);
val[u] = 0;
sort(all(alldp),cmp);
for(int i = 0 ; i < sz(alldp) && sz(dp[u]) < SZ+7 ; i++) {
if (ok[alldp[i]]) continue;
ok[alldp[i]] = 1;
dp[u].pb({val[alldp[i]],alldp[i]});
}
for(auto x:alldp) ok[x] = 0;
}
vector<bool> yes(n+1,0);
for(int i = 0 ; i < q ; i++) {
int dest,k;
scanf("%d %d",&dest,&k);
vector<int> vec;
for(int j = 0 ; j < k ; j++) {
int v;
scanf("%d",&v);
vec.pb(v);
yes[v] = 1;
}
if (k < SZ) {
bool ok = 0;
for(auto p:dp[dest]) {
if (yes[p.S]) continue;
printf("%d\n",p.F);
ok = 1;
break;
}
if (!ok) puts("-1");
} else {
memset(tmp,-1,sizeof tmp);
for(auto u:toposort) {
if (!yes[u]) tmp[u] = 0;
for(auto v:tg[u]) {
if (tmp[v] != -1) tmp[u] = max(tmp[u],tmp[v]+1);
}
}
printf("%d\n",tmp[dest]);
}
for(auto v:vec) yes[v] = 0;
}
}
int main() {
// freopen("in","r",stdin);
// freopen("out","w",stdout);
int T = 1;
//scanf("%d",&T);
while(T--) solve();
return 0;
}
