/***Farhan132***/
#include <bits/stdc++.h>
using namespace std;
typedef int ll;
typedef unsigned long long ull;
typedef double dd;
typedef vector<ll> vll;
typedef pair<ll , ll> ii;
typedef vector< ii > vii;
typedef pair < ll , pair < ll , ll > > cm;
#define ff first
#define ss second
#define pb push_back
#define in insert
#define f0(b) for(int i=0;i<(b);i++)
#define f00(b) for(int j=0;j<(b);j++)
#define f1(b) for(int i=1;i<=(b);i++)
#define f11(b) for(int j=1;j<=(b);j++)
#define f2(a,b) for(int i=(a);i<=(b);i++)
#define f22(a,b) for(int j=(a);j<=(b);j++)
#define sf(a) scanf("%lld",&a)
#define sff(a,b) scanf("%lld %lld", &a , &b)
#define pf(a) printf("%lld\n",a)
#define pff(a,b) printf("%lld %lld\n", a , b)
#define PI 3.14159265359
#define bug printf("**!\n")
#define mem(a , b) memset(a, b ,sizeof(a))
#define front_zero(n) __builtin_clzll(n)
#define back_zero(n) __builtin_ctzll(n)
#define total_one(n) __builtin_popcountll(n)
#define clean fflush(stdout)
const ll mod = (ll)1e9 + 7;
const ll maxn = (ll)1e5 + 5;
const int nnn = 1048590;
const int inf = numeric_limits<int>::max()-1;
//const ll INF = numeric_limits<ll>::max()-1;
//const ll INF = 1e18;
ll dx[]={0,1,0,-1};
ll dy[]={1,0,-1,0};
ll dxx[]={0,1,0,-1,1,1,-1,-1};
ll dyy[]={1,0,-1,0,1,-1,1,-1};
const ll N = 318;
ll val[maxn] , vis[maxn] , dp[maxn];
vector < ll > v[maxn], g[maxn];
vector < ii > f[maxn];
vector < ii > merge(vector <ii> &a, vector < ii > &b){
vector < ii > ans;
ll p1 = 0 , p2 = 0;
while(p1 + p2 < a.size() + b.size()){
if(ans.size() == N+2) break;
if(p1 < a.size() && vis[a[p1].ff]){p1++; continue;}
if(p2 < b.size() && vis[b[p2].ff]){p2++; continue;}
if(p1 == a.size()){ vis[b[p2].ff]=1; ans.pb({b[p2++].ff ,b[p2-1].ss + 1 }) ; continue;}
if(p2 == b.size()){ vis[a[p1].ff]=1; ans.pb({a[p1++].ff ,a[p1-1].ss}) ; continue;}
if(b[p2].ss+1 > a[p1].ss)
vis[b[p2].ff]=1, ans.pb({b[p2++].ff ,b[p2-1].ss + 1 }) ;
else
vis[a[p1].ff]=1, ans.pb({a[p1++].ff ,a[p1-1].ss}) ;
}
for(auto [u , y] : ans) vis[u] = 0;
return ans;
}
bool comp(ll a, ll b){
return val[a] < val[b];
}
void solve(){
mem(vis, 0);
ll n , m , q;
cin >> n >> m >> q;
for(ll i = 1; i <= m; i++){
ll x , y;
cin >> x >> y;
v[y].pb(x);
}
for(ll i = 1; i <= n; i++){
val[i] = 0;
f[i].pb({i, 0});
for(auto u : v[i]){
f[i] = merge(f[i] , f[u]);
}
// sort(f[i].begin() , f[i].end() , comp);
}
vector < ll > c;
while(q--){
ll node , t , x;
cin >> node >> t;
for(auto u : c) vis[u] = 0;
c.clear();
f1(t) cin >> x , c.pb(x) , vis[x] = 1;
if(t >= N){
mem(dp, 0);
for(auto u : c) dp[u] = -1;
for(ll i = 1; i <= node; i++){
for(auto u : v[i]){
if(dp[u] == -1) continue;
dp[i] = max(dp[i] , dp[u]+1);
}
}
cout << dp[node] << '\n';
}else{
bool ok = 0;
for(auto [u , y] : f[node]){
if(!vis[u]){
cout << y << '\n';
ok = 1;
break;
}
}
if(!ok) cout << "-1\n";
}
}
return;
}
int main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#else
// freopen("cbarn2.in", "r", stdin);
// freopen("cbarn2.out", "w", stdout);
ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
#endif
//cout << fixed << setprecision(10);
// work();
// mem(b,0);
ll T;
T=1;
//cin >> T;
//scanf("%lld",&T);
// ll CT = 0;
//work();
while(T--){
//cout << "Case " << ++CT <<": " ;
//printf("Case %lld: ",++CT);
solve();
}
return 0;
}
