/*
_ _ _ __ __ _____
/\ | | /\ | | | | | \/ |/ ____|
/ \ | |__ ___ / \ | |__ __| | ___ | \ / | |
/ /\ \ | '_ \ / _ \ / /\ \ | '_ \ / _` |/ _ \| |\/| | |
/ ____ \| |_) | (_) / ____ \| |_) | (_| | (_) | | | | |____
/_/ \_\_.__/ \___/_/ \_\_.__/ \__,_|\___/|_| |_|\_____|
*/
// 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 = 300;
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];
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));
for(auto u:toposort) {
vector<int> ptr(sz(tg[u]),0);
int ssz = sz(tg[u]);
while(sz(dp[u]) < 2*SZ) {
pair<pii,int> mx = {{-1,-1},-1}; // {{dist[u],u},ptridx}
int cnt = 0;
for(auto v:tg[u]) {
if (ptr[cnt] >= sz(dp[v])) {cnt++;continue;}
mx = mx < pair<pii,int>{dp[v][ptr[cnt]],cnt} ? pair<pii,int>{dp[v][ptr[cnt]],cnt}:mx;
cnt++;
}
if (mx.S == -1) break;
cnt = 0;
for(auto v:tg[u]) {
if (ptr[cnt] >= sz(dp[v])) {cnt++;continue;}
if (dp[v][ptr[cnt]].S == mx.F.S) ptr[cnt]++;
cnt++;
}
mx.F.F++;
dp[u].pb(mx.F);
}
dp[u].pb({0,u});
}
reverse(all(toposort));
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 {
int ans = -1;
for(auto u:toposort) {
if (u == dest) tmp[u] = 0;
else tmp[u] = -1;
for(auto v:g[u]) {
if (tmp[v] == -1) continue;
tmp[u] = max(tmp[u],tmp[v]+1);
}
if (!yes[u]) ans = max(ans,tmp[u]);
}
printf("%d\n",ans);
}
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;
}
