#include<bits/stdc++.h>
using namespace std;
int n, m, k, vis[35], cnt[15], best = 2e9;
vector <int> te[35], br[35];
void Try(int curs, int curm)
{
    if (curs > n)
    {
        best = min(best, curm);
        return;
    }
    if (curm > best) return;
    for (int i : te[curs])
    {
        bool ok = true;
        for (int j : br[curs])
        {
            if (vis[j] == i)
            {
                ok = false;
                break;
            }
        }
        if (ok)
        {
            vis[curs] = i;
            cnt[i]++;
            Try(curs + 1, max(curm, cnt[i]));
            cnt[i]--;
            vis[curs] = 0;
        }
    }
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    if (fopen("input.txt", "r"))
        assert(freopen("input.txt", "r", stdin));
    cin >> m >> n;
    for (int i = 1; i <= m; ++i)
    {
        int x; cin >> x;
        while (x--)
        {
            int u; cin >> u;
            te[u].push_back(i);
        }
    }
    cin >> k;
    for (int i = 1; i <= k; ++i)
    {
        int u, v;
        cin >> u >> v;
        br[u].push_back(v);
        br[v].push_back(u);
    }
    Try(1, 0);
    if (best == 2e9) best = -1;
    cout << best;
}