#include <algorithm>
#include <iostream>
#include <numeric>
#include <cstring>
#include <iomanip>
#include <vector>
#include <bitset>
#include <stack>
#include <queue>
#include <cmath>
#include <set>
#include <map>
#define endl '\n'
#define X first
#define Y second
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
const int maxn = 2e5+10;
const int sq = 202;
const int inf = 1e9;
pii dst[maxn][sq];
vector<int> G[maxn];
pii tmp[sq*2+1];
bool _vis[maxn+1];
bool *vis = _vis+1;
inline void mrg(int a, int b) // a < b
{
int pa = 0;
int pb = 0;
while(pa < sq or pb < sq)
{
if(pa == sq or (pb < sq and dst[b][pb].X > dst[a][pa].X+1) )
{
tmp[pa+pb] = dst[b][pb];
pb++;
}
else
{
tmp[pa+pb] = dst[a][pa];
tmp[pa+pb].X++;
pa++;
}
}
int c = 0;
for(int i = 0; i < sq+sq and c < sq; i++)
{
if(tmp[i].Y != -1 and !vis[tmp[i].Y])
{
vis[tmp[i].Y] = true;
dst[b][c++] = tmp[i];
}
}
for(int i = 0; i < sq+sq; i++)
if(tmp[i].Y != -1)
vis[tmp[i].Y] = false;
}
bool dead[maxn];
int dtmp[maxn];
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(0);
int n, m, q; cin >> n >> m >> q;
for(int i = 0; i < m; i++)
{
int a, b; cin >> a >> b;
a--; b--;
G[b].push_back(a);
}
for(int i = 0; i < n; i++)
{
fill(dst[i], dst[i]+sq, pii(-1, -1));
dst[i][0] = pii(0, i);
for(int j: G[i])
mrg(j, i);
}
while(q--)
{
int t, k; cin >> t >> k;
t--;
vector<int> dd(k);
for(int i = 0; i < k; i++)
{
cin >> dd[i];
dd[i]--;
dead[dd[i]] = true;
}
int ans = -1;
if(k < sq)
{
for(int i = 0; i < sq; i++)
if(!dead[dst[t][i].Y])
ans = max(ans, dst[t][i].X);
}
else
{
for(int i = 0; i <= t; i++)
{
if(dead[i])
dtmp[i] = -1;
else
dtmp[i] = 0;
for(int j: G[i])
{
if(dtmp[j] != -1)
dtmp[i] = max(dtmp[i], dtmp[j]+1);
}
}
ans = dtmp[t];
}
cout << ans << endl;
for(int x: dd)
dead[x] = false;
}
return 0;
}
