#include <bits/stdc++.h>
using namespace std;
using ll = long long;
//#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define Lg(x) 31 - __builtin_clz(x)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void setupIO(){
#define name "Whisper"
//Phu Trong from Nguyen Tat Thanh High School for gifted student
srand(time(NULL));
cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
cout << fixed << setprecision(10);
}
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int numNode, numQuery, numEdge;
vector<int> G[MAX];
vector<pair<int, int>> opt[MAX];
//opt(i) save the node has length x end at i
#define BLOCK 222
int dis[MAX], vis[MAX];
void Whisper(){
cin >> numNode >> numEdge >> numQuery;
for (int i = 1; i <= numEdge; ++i){
int u, v; cin >> u >> v;
//change the direction of DAG
G[v].emplace_back(u);
}
// O(n * sqrt(n))
// solving for case: c < BLOCK
// because the number of unsatisfied node is smaller than BLOCK
//=> the opt[u] size at most BLOCK is enough
// we can proved that always exist a beavers that not busy in opt[u]
for (int u = 1; u <= numNode; ++u){
vector<int> current;
for(int &v : G[u]){
for (pair<int, int>& x : opt[v]){
if (vis[x.second] == u){
maximize(dis[x.second], x.first + 1);
}
else {
vis[x.second] = u;
dis[x.second] = x.first + 1; current.push_back(x.second);
}
}
}
opt[u].emplace_back(0, u);
for (int &v : current){
opt[u].emplace_back(dis[v], v);
}
sort(opt[u].rbegin(), opt[u].rend());
while ((int)opt[u].size() > BLOCK) opt[u].pop_back();
}
vector<int> busy(numNode + 1, 0);
for (int t = 1; t <= numQuery; ++t){
int x, c; cin >> x >> c;
vector<int> rback;
for(int i = 1; i <= c; ++i){
int v; cin >> v;
rback.push_back(v);
busy[v] = 1;
}
if (c >= BLOCK){
// using dp on DAG to solve this with total complexivity O(n)
vector<int> dp(numNode + 1, -INF);
for (int u = 1; u <= x; ++u){
if (!busy[u]) maximize(dp[u], 0);
for (int &v : G[u]){
maximize(dp[u], dp[v] + 1);
}
}
maximize(dp[x], -1);
cout << dp[x] << '\n';
}
else{
int ans = -1;
for (pair<int, int> v : opt[x]) if(!busy[v.second]){
maximize(ans, v.first);
}
cout << ans << '\n';
}
for (auto&v : rback) busy[v] = 0;
}
}
signed main(){
setupIO();
int Test = 1;
// cin >> Test;
for ( int i = 1 ; i <= Test ; i++ ){
Whisper();
if (i < Test) cout << '\n';
}
}
