#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define fi first
#define se second
inline int in() {
int result = 0;
char ch = getchar_unlocked();
while(true) {
if(ch >= '0' && ch <= '9')
break;
ch = getchar_unlocked();
}
result = ch-'0';
while(true) {
ch = getchar_unlocked();
if (ch < '0' || ch > '9')
break;
result = result*10 + (ch - '0');
}
return result;
}
inline void out(int x) {
if(!x) {
putchar_unlocked('0');
return;
}
if(x<0) {
putchar_unlocked('-');
x=-x;
}
int rev=x, c=0;
while(!(rev%10)) {
++c;
rev/=10;
}
rev=0;
while(x) {
rev=rev*10+x%10;
x/=10;
}
while(rev) {
putchar_unlocked(rev%10+'0');
rev/=10;
}
while(c--)
putchar_unlocked('0');
}
const int mxN=1e5, bs=10;
int n, m, q, dp2[mxN], c[mxN];
vector<int> adj[mxN];
vector<pii> dp1[mxN];
priority_queue<pii, vector<pii>, greater<pii>> pq;
bool a[mxN];
int main() {
n=in(), m=in(), q=in();
while(m--) {
int u=in()-1, v=in()-1;
adj[v].push_back(u);
}
for(int i=0; i<n; ++i) {
pq.push({0, i});
for(int v : adj[i]) {
for(pii p : dp1[v]) {
pq.push({p.fi+1, p.se});
if(pq.size()>bs)
pq.pop();
}
}
while(!pq.empty()) {
dp1[i].push_back(pq.top());
pq.pop();
}
}
while(q--) {
int t=in()-1, y=in(), ans=-1;
for(int i=0; i<y; ++i) {
c[i]=in()-1;
a[c[i]]=1;
}
if(y>bs) {
memset(dp2, -1, 4*(t+1));
for(int i=0; i<=t; ++i) {
dp2[i]=a[i]?-n:0;
for(int v : adj[i])
dp2[i]=max(dp2[v]+1, dp2[i]);
}
ans=max(dp2[t], ans);
} else {
for(int i=dp1[t].size()-1; i>=0; --i) {
if(a[dp1[t][i].se])
continue;
ans=dp1[t][i].fi;
break;
}
}
for(int i=0; i<y; ++i)
a[c[i]]=0;
out(ans);
putchar_unlocked('\n');
}
}
