#ifndef LOCAL
#pragma GCC Optimize("O3,Ofast,unroll-loops")
#pragma GCC Target("bmi,bmi2,avx,avx2")
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define int ll
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin() (x).rend()
#ifndef LOCAL
#define endl "\n"
#endif
mt19937 rnd(11);
void solve() {
int n, m;
cin >> n >> m;
int L = 128;
vector<vector<int>> graph(n);
for (int i = 0; i < m; ++i) {
int a, b;
cin >> a >> b;
--a; --b;
graph[a].pb(b);
graph[b].pb(a);
}
int k;
cin >> k;
vector<pii> bad(n, mp(0, 0));
map<pii, pii> badE;
for (int i = 0; i < k; ++i) {
int sz;
cin >> sz;
vector<int> v(sz);
for (auto &x : v) {
cin >> x;
--x;
}
for (int j = 0; j < sz; ++j) {
bad[v[j]] = mp(sz, j);
badE[mp(v[j], v[(j + 1) % v.size()])] = mp(sz, j);
badE[mp(v[(j + 1) % v.size()], v[j])] = mp(sz, j);
}
}
vector<int> d(n, 1e9);
set<pii> marked;
d[0] = 0;
queue<pii> q;
q.push(mp(0, 0));
while (!q.empty()) {
auto p = q.front();
q.pop();
if (marked.count(p)) {
continue;
}
marked.insert(p);
int v = p.f;
int t = p.s;
if (t + 1 < d[v] + L) {
q.push(mp(v, t + 1));
}
for (auto &u : graph[v]) {
if ((bad[u].f == 0 || ((t + 1) % bad[u].f != bad[u].s)) && (badE[mp(v, u)].f == 0 || (t % badE[mp(v, u)].f != badE[mp(v, u)].s))) {
if (d[u] == 1e9) {
d[u] = t + 1;
q.push(mp(u, t + 1));
} else if (d[u] + L > t + 1) {
q.push(mp(u, t + 1));
}
}
}
}
if (d.back() == 1e9) {
cout << "impossible" << endl;
} else {
cout << d.back() << endl;
}
}
signed main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#else
ios::sync_with_stdio(false);
cin.tie(0);
#endif
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
