#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define ll long long #define ld long double #define ull unsigned long long #define ff first #define ss second #define pii pair<int,int> #define pll pair<long long, long long> #define vi vector<int> #define vl vector<long long> #define pb push_back #define rep(i, b) for(int i = 0; i < (b); ++i) #define rep2(i,a,b) for(int i = a; i <= (b); ++i) #define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c) #define count_bits(x) __builtin_popcountll((x)) #define all(x) (x).begin(),(x).end() #define siz(x) (int)(x).size() #define forall(it,x) for(auto& it:(x)) using namespace __gnu_pbds; using namespace std; typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set; //mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());} //ll los(ll a, ll b) {return a + (mt() % (b-a+1));} const int INF = 1e9+50; const ll INF_L = 1e18+40; const ll MOD = 1e9+7; const int sqr = 320; vi graph[100001]; vi graph2[100001]; int deg[100001]; bool is_out[100001]; int dp[100001]; vector<pii> best[100001]; bool was[100001]; vi ls; int n,m,q2; void big_query(vi x, int T) { forall(it,ls) { if(!is_out[it]) dp[it] = 0; else dp[it] = -1e9; forall(it2,graph[it]) dp[it] = max(dp[it],dp[it2]+1); if(it == T) { cout << max(-1,dp[it]) << "\n"; } } } vector<pii> merge_dp(vector<pii>& v1, vector<pii>& v2) { int p1 = 0; int p2 = 0; vector<pii> ans; forall(it,v2) it.ff++; rep(i,min(siz(v1)+siz(v2),sqr)) { while(p1 < siz(v1) && was[v1[p1].ss]) p1++; while(p2 < siz(v2) && was[v2[p2].ss]) p2++; if(p1 == siz(v1) && p2 == siz(v2)) break; if(p1 == siz(v1)) {ans.pb(v2[p2++]);was[v2[p2-1].ss]=1;} else if(p2 == siz(v2)) {ans.pb(v1[p1++]);was[v1[p1-1].ss]=1;} else { if(v1[p1].ff >= v2[p2].ff) {ans.pb(v1[p1++]);was[v1[p1-1].ss]=1;} else {ans.pb(v2[p2++]);was[v2[p2-1].ss]=1;} } } forall(it,v2) it.ff--; forall(it,ans) was[it.ss] = 0; return ans; } int main() { ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); //random_start(); cin >> n >> m >> q2; rep(i,m) { int a,b; cin >> a >> b; graph[b].pb(a); graph2[a].pb(b); } rep2(i,1,n) deg[i] = siz(graph[i]); queue<int> q; rep2(i,1,n) if(deg[i] == 0) q.push(i); while(!q.empty()) { int t = q.front(); q.pop(); ls.pb(t); forall(it,graph2[t]) { deg[it]--; if(deg[it] == 0) q.push(it); } } forall(it,ls) { best[it] = {{0,it}}; forall(it2,graph[it]) { best[it] = merge_dp(best[it],best[it2]); } } rep(qq,q2) { int t,y; cin >> t >> y; vi x(y); rep(j,y) cin >> x[j]; forall(it,x) is_out[it] = 1; if(y >= sqr-5) big_query(x,t); else { int ans = -1; forall(it,best[t]) if(!is_out[it.ss]) ans = max(ans,it.ff); cout << ans << "\n"; } forall(it,x) is_out[it] = 0; } }