#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int sq = 350,MAXN = 1e5+1;
bool take[MAXN],vis[MAXN];
int dp[MAXN];
vector<int>adj[MAXN],radj[MAXN];
vector<pii>good[MAXN];
int main()
{
owo
int n,m,q;
cin>>n>>m>>q;
for(int i=0;i<m;i++){
int v,u;
cin>>v>>u;
adj[v].pb(u);
radj[u].pb(v);
}
//good[i] stores the sq longest paths to i
//in decreasing order
for(int i=1;i<=n;i++){
for(int x:radj[i]){
vector<pii>fin;
good[x].pb({0,x});
//duplicates are dangerous
int a = 0,b=0;
int sa = sz(good[x]);
int sb = sz(good[i]);
while(sz(fin)<sq && (a<sa || b < sb)){
if(b == sb || (a!=sa && good[x][a].fi+1 >= good[i][b].fi)){
good[x][a].fi++;
fin.pb(good[x][a]);
vis[good[x][a].se] = 1;
good[x][a].fi--;
a++;
}else{
fin.pb(good[i][b]);
vis[good[i][b].se] = 1;
b++;
}
while(a<sa && vis[good[x][a].se])a++;
while(b<sb && vis[good[i][b].se])b++;
}
good[x].pop_back();
for(auto z:fin)vis[z.se] = 0;
swap(good[i],fin);
}
}
cout<<'\n';
while(q--){
int t,y;
cin>>t>>y;
vector<int>c(y);
for(int i=0;i<y;i++){
cin>>c[i];
take[c[i]] = 1;
}
int ans = -1;
if(y>=350){ //this should be correct
for(int i=1;i<=n;i++)dp[i] = -1;
dp[t] = 0;
if(!take[t])ans = 0;
for(int i=t-1;i;i--){
for(int x:adj[i]){
if(dp[x]!=-1)dp[i] = max(dp[i],dp[x]+1);
}
if(!take[i])ans = max(ans,dp[i]);
}
}else{
for(auto x:good[t]){
if(!take[x.se]){
ans = x.fi;
break;
}
}
if(!take[t])ans = max(ans,0);
}
cout<<ans<<'\n';
for(int i=0;i<y;i++)take[c[i]] = 0;
}
}
