#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2,avx512f")
#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops")
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define rep(a) rep1(i,a)
#define rep1(i,a) rep2(i,0,a)
#define rep2(i,b,a) for(int i=(b); i<((int)(a)); i++)
#define rep3(i,b,a) for(int i=(b); i>=((int)(a)); i--)
#define all(a) a.begin(),a.end()
#define pii pair<int,int>
#define pb push_back
#define inf 1010000000
//#define inf 4000000000000000000
#define eps 1e-9
#define sz(a) ((int)a.size())
#define pow2(x) (1ll<<(x))
#define ceiling(a,b) (((a)+(b)-1)/(b))
#ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {static int cnt=0;cerr << x << endl;cnt++;if(cnt>1000) exit(0);}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}
#else
#define bug(...) 826
#endif
inline char readchar(){
const int maxn=1000000;
static char buf[maxn],*p=buf,*q=buf;
if(p==q&&(q=(p=buf)+fread(buf,1,maxn,stdin))==buf) return EOF;
else return *p++;
}
inline int readint(){
int c=readchar(),x=0,neg=0;
while((c<'0'||c>'9')&&c!='-'&&c!=EOF) c=readchar();
if(c=='-') neg=1,c=readchar();
while(c>='0'&&c<='9') x=(x<<3)+(x<<1)+(c^'0'),c=readchar();
return neg?-x:x;
}
const int Mod=1000000007,Mod2=998244353;
const int MOD=Mod;
const int maxn=100005;
//i_am_noob
const int K=205;
int n,m,pos[maxn][K],val[maxn][K],maxx[maxn],q,x,k;
vector<int> adj[maxn],vec,vec1;
bool vis[maxn];
signed main(){
ios_base::sync_with_stdio(0),cin.tie(0);
#ifdef i_am_noob
freopen("input1.txt","r",stdin);
freopen("output1.txt","w",stdout);
freopen("output2.txt","w",stderr);
#endif
n=readint(),m=readint(),q=readint();
rep(m){
int u,v;
u=readint(),v=readint();
adj[v-1].pb(u-1);
}
rep(n) maxx[i]=-inf;
rep(n){
rep1(j,K) val[i][j]=-inf;
vec.clear(),vec1.clear();
for(auto v: adj[i]) rep1(j,K) maxx[pos[v][j]]=max(maxx[pos[v][j]],val[v][j]+1),vec.pb(pos[v][j]);
maxx[i]=max(maxx[i],0),vec.pb(i);
for(auto j: vec) if(maxx[j]>=0&&!vis[j]) vec1.pb(j),vis[j]=1;
sort(all(vec1),[](int p, int q){return maxx[p]>maxx[q];});
rep1(j,min(sz(vec1),K)) val[i][j]=maxx[vec1[j]],pos[i][j]=vec1[j];
for(auto j: vec1) vis[j]=0,maxx[j]=-inf;
}
memset(vis,0,sizeof vis);
while(q--){
x=readint(),k=readint();
x--;
vec.clear();
vec.resize(k);
rep(k) vec[i]=readint();
rep(k) vec[i]--,vis[vec[i]]=1;
if(k<K){
rep(K) if(val[x][i]<0||!vis[pos[x][i]]){
cout << (val[x][i]<0?-1:val[x][i]) << "\n";
break;
}
rep(k) vis[vec[i]]=0;
continue;
}
rep(x+1) maxx[i]=-inf;
rep(x+1){
for(auto v: adj[i]) maxx[i]=max(maxx[i],maxx[v]+1);
if(!vis[i]) maxx[i]=max(maxx[i],0);
}
cout << (maxx[x]<0?-1:maxx[x]) << "\n";
rep(k) vis[vec[i]]=0;
}
return 0;
}
