#include <bits/stdc++.h>
#define int long long
#define vt vector
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define ff first
#define ss second
#define dbg(x) cerr << #x << " = " << x << '\n'
#define bit(x, i) ((x) >> (i) & 1)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vvt = vt< vt<int> >;
const int N = 1e6 + 5, mod = 1e9 + 7, B = 200;
const ll inf = 1e18 + 7, LIM = (1ll << 60);
const double eps = 1e-6;
int n, m, q, dp[N], c[N];
bool used[N], can[N];
vt<int> g[N];
vt<pii> f[N];
void solve () {
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int x, y;
cin >> x >> y;
g[x].pb(y);
}
for (int i = 1; i <= n; i++) f[i].pb({0, i});
for (int i = 1; i <= n; i++) {
sort(all(f[i]));
reverse(all(f[i]));
vt<pii> nf;
for (auto [dist, v]: f[i]) used[v] = 0;
for (auto [dist, v]: f[i]) {
if (used[v]) continue;
used[v] = 1;
nf.pb({dist, v});
if (sz(nf) == B) break;
}
f[i] = nf;
for (auto [dist, v]: f[i]) {
for (auto to: g[i]) f[to].pb({dist + 1, v});
}
}
fill(can, can + n + 1, 1);
while (q--) {
int t, y;
cin >> t >> y;
for (int i = 1; i <= y; i++) {
cin >> c[i];
can[c[i]] = 0;
}
int ans = -1;
if (y >= B) {
dp[t] = 0;
for (int i = t - 1; i >= 1; i--) {
dp[i] = -1;
for (auto to: g[i]) {
if (to <= t && dp[to] != -1) dp[i] = max(dp[i], dp[to] + 1);
}
}
for (int i = 1; i <= t; i++) {
if (can[i]) ans = max(ans, dp[i]);
}
}
else {
for (auto [dist, v]: f[t]) {
if (can[v]) {
ans = dist;
break;
}
}
}
cout << ans << '\n';
for (int i = 1; i <= y; i++) can[c[i]] = 1;
}
cout << '\n';
}
bool testcases = 0;
signed main() {
#ifdef ONLINE_JUDGE
freopen(".in", "r", stdin);
freopen(".out", "w", stdout);
#endif
cin.tie(0) -> sync_with_stdio(0);
int test = 1;
if (testcases) cin >> test;
for (int cs = 1; cs <= test; cs++) {
solve();
}
}
