#include <bits/stdc++.h>
#define FOR(i,x,n) for(int i=x; i<n; i++)
#define F0R(i,n) FOR(i,0,n)
#define ROF(i,x,n) for(int i=n-1; i>=x; i--)
#define R0F(i,n) ROF(i,0,n)
#define WTF cout << "WTF" << endl
#define IOS ios::sync_with_stdio(false); cin.tie(0)
#define F first
#define S second
#define pb push_back
#define ALL(x) x.begin(), x.end()
#define RALL(x) x.rbegin(), x.rend()
using namespace std;
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
const int MAXN = 1e5 + 7;
const int ALPHA = 27;
const int INF = 1e9 + 7;
const int MOD = 1e9 + 7;
const int LOG = 22;
const int SQ = 320;
int n, m, q, cnt;
int skip[MAXN], mem[MAXN], marked[MAXN];
int tmp[SQ][2], dp[MAXN][SQ][2];
bool colored[MAXN];
VI adj[MAXN], order, radj[MAXN];
void init() {
cin >> n >> m >> q;
int u, v;
F0R(i, m) {
cin >> u >> v;
adj[--u].pb(--v);
radj[v].pb(u);
}
return;
}
void dfs(int now) {
colored[now] = 1;
for(int on : adj[now]) if (!colored[on]) dfs(on);
order.pb(now);
return;
}
inline int merge(int (&a)[SQ][2], int (&b)[SQ][2], int (&c)[SQ][2]) {
cnt++;
int aptr = 0, bptr = 0, cptr = 0;
F0R(i, SQ) c[i][0] = c[i][1] = 0;
while(aptr < SQ && bptr < SQ && a[aptr][0] && b[bptr][0] && cptr < SQ) {
if (a[aptr][0] > b[bptr][0]) {
if (marked[ a[aptr][1] ] == cnt) {
aptr++;
continue;
}
c[cptr][0] = a[aptr][0];
c[cptr][1] = a[aptr][1];
marked[ a[aptr][1] ] = cnt;
aptr++; cptr++;
}
else {
if (marked[ b[bptr][1] ] == cnt) {
bptr++;
continue;
}
c[cptr][0] = b[bptr][0] + 1;
c[cptr][1] = b[bptr][1];
marked[ b[bptr][1] ] = cnt;
bptr++; cptr++;
}
}
while(aptr < SQ && a[aptr][0] && cptr < SQ) {
if (marked[ a[aptr][1] ] == cnt) {
aptr++;
continue;
}
c[cptr][0] = a[aptr][0];
c[cptr][1] = a[aptr][1];
marked[ a[aptr][1] ] = cnt;
aptr++; cptr++;
}
while(bptr < SQ && b[bptr][0] && cptr < SQ) {
if (marked[ b[bptr][1] ] == cnt) {
bptr++;
continue;
}
c[cptr][0] = b[bptr][0] + 1;
c[cptr][1] = b[bptr][1];
marked[ b[bptr][1] ] = cnt;
bptr++; cptr++;
}
return cptr;
}
void precalc() {
F0R(i, n) if (!colored[i]) dfs(i);
reverse(ALL(order));
/*for(int on : order) cout << on << ' ';
cout << endl;*/
F0R(i, n) {
int now = order[i];
dp[now][0][0] = 1;
dp[now][0][1] = now;
for(int on : radj[now]) {
merge(dp[now], dp[on], tmp);
F0R(i, SQ) {
dp[now][i][0] = tmp[i][0];
dp[now][i][1] = tmp[i][1];
}
}
}
return;
}
void calc(int p) {
fill(mem, mem + MAXN, 0);
F0R(i, n) {
int now = order[i];
mem[now] = 1;
if (skip[now] == p) mem[now] = -INF;
for(int on : radj[now])
mem[now] = max(mem[now], mem[on] + 1);
}
return;
}
#define endl '\n'
int main() {
IOS;
init();
precalc();
/*F0R(i, n) {
cout << i + 1 << " : ";
for(int on : radj[i]) cout << on + 1 << ' ';
cout << endl;
}*/
//F0R(i, 5) cout << dp[3][i][0] << ' ' << dp[3][i][1] << endl;
FOR(p, 1, q + 1) {
int t, k, x;
cin >> t >> k;
t--;
F0R(i, k) {
cin >> x; x--;
skip[x] = p;
}
/*F0R(i, n) cout << skip[i] << ' ';
cout << endl;*/
if (k < SQ) {
bool done = 0;
F0R(i, SQ) if (skip[ dp[t][i][1] ] != p) {
cout << dp[t][i][0] - 1 << endl;
done = 1;
break;
}
if (!done) cout << -1 << endl;
}
else {
calc(p);
cout << (mem[t] > 0 ? mem[t] : -1) << endl;
}
}
}
