#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define NAME ""
#define eb emplace_back
#define pii pair<int, int>
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define REP(i, a, b) for (int i = (a), _b = (b); i >= _b; i--)
#define FORD(i, a, b, x) for (int i = (a), _b = (b); i <= _b; i += x)
const int MAX = 100005, BLOCK = sqrt(MAX) + 1, LOG = __lg(MAX) + 1, mod = 1e9 + 7;
const int INF = 1e18;
typedef long long ll;
namespace Solution
{
int n, m, q;
vector<int> adj[MAX], radj[MAX];
vector<pii> vi[MAX];
bool vis[MAX];
int dist[MAX];
void solve()
{
cin >> n >> m >> q;
FOR(i, 1, m)
{
int u, v;
cin >> u >> v;
adj[u].eb(v);
radj[v].eb(u);
}
FOR(i, 1, n)
{
vi[i].clear();
vi[i].eb(0, i);
}
FOR(u, 1, n)
{
for (auto v : radj[u])
{
vector<pii> tmp;
vi[v].eb(0, v);
int ni = vi[u].size();
int nj = vi[v].size();
int i = 0, j = 0;
while (tmp.size() < BLOCK && (i < ni || j < nj))
{
if (i == ni || (j < nj && vi[v][j].fi + 1 >= vi[u][i].fi))
{
tmp.eb(vi[v][j].fi + 1, vi[v][j].se);
vis[vi[v][j].se] = true;
j++;
}
else
{
tmp.eb(vi[u][i]);
vis[vi[u][i].se] = true;
i++;
}
while (i < ni && vis[vi[u][i].se])
i++;
while (j < nj && vis[vi[v][j].se])
j++;
}
vi[v].pop_back();
for (auto &p : tmp)
vis[p.se] = false;
swap(vi[u], tmp);
}
}
while (q--)
{
int t, y;
cin >> t >> y;
vector<int> blocked;
blocked.reserve(y);
FOR(i, 1, y)
{
int x;
cin >> x;
vis[x] = true;
blocked.eb(x);
}
if (y < BLOCK)
{
int ans = -1;
for (auto &p : vi[t])
if (p.fi > ans && !vis[p.se])
ans = p.fi;
if (!vis[t])
ans = max(ans, 0);
cout << ans << '\n';
}
else
{
int ans = -1;
FOR(i, 1, n)
{
dist[i] = -1;
}
dist[t] = 0;
if (!vis[t])
ans = 0;
REP(i, t - 1, 1)
{
for (auto v : adj[i])
{
if (dist[v] != -1)
{
dist[i] = max(dist[i], dist[v] + 1);
}
}
if (dist[i] != -1 && !vis[i])
ans = max(ans, dist[i]);
}
cout << ans << '\n';
}
for (int x : blocked)
vis[x] = false;
}
}
}
signed main()
{
if (fopen(NAME ".inp", "r"))
{
freopen(NAME ".inp", "r", stdin);
freopen(NAME ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
Solution::solve();
return 0;
}
