#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define sz(a) (int)a.size()
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
typedef long long ll;
using namespace std;
const int INF = 1e9;
void solve() {
int n, m;
cin >> n >> m;
vector<vector<int>> gr(n);
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
u--, v--;
gr[u].push_back(v);
gr[v].push_back(u);
}
int k;
cin >> k;
vector<vector<int>> v(k);
vector<int> head(k);
vector<int> idx(n, -1), pos(n, -1);
int vertex_cnt = n;
for (int i = 0; i < k; ++i) {
int len;
cin >> len;
head[i] = vertex_cnt;
vertex_cnt += len * len;
v[i].resize(len);
for (int j = 0; j < len; ++j) {
cin >> v[i][j];
v[i][j]--;
idx[v[i][j]] = i;
pos[v[i][j]] = j;
for (int it = 0; it < len; ++it) {
idx.push_back(i);
pos.push_back(j);
}
}
}
auto get_v = [&](int i, int d) {
if (idx[i] == -1) return i;
int j = idx[i];
return head[j] + sz(v[j]) * pos[i] + d % sz(v[j]);
};
auto get_orig = [&](int i) {
if (idx[i] == -1) return i;
int j = idx[i];
return v[j][pos[i]];
};
auto watchman_at = [&](int d, int i) {
return v[i][d % sz(v[i])];
};
auto when_watchman = [&](int d, int i) {
int j = idx[i];
assert(j != -1);
int res = d - d % sz(v[j]) + pos[i];
if (res >= d) {
return res;
} else {
return res + sz(v[j]);
}
};
for (int i = 0; i < n; ++i) {
sort(all(gr[i]), [&](int a, int b) {
return idx[a] > idx[b];
});
}
vector<int> dist(vertex_cnt, INF);
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> st;
auto update = [&](int i, int d) {
i = get_v(i, d);
if (dist[i] > d) {
// cerr << "updated " << get_orig(i) << " with " << d << '\n';
dist[i] = d;
st.push({dist[i], i});
}
};
update(0, 0);
while (!st.empty()) {
auto [d, i] = st.top();
st.pop();
if (dist[i] != d) continue;
i = get_orig(i);
while (!gr[i].empty() && idx[gr[i].back()] == -1) {
int to = gr[i].back();
gr[i].pop_back();
update(to, d + 1);
}
for (int to : gr[i]) {
if (idx[i] == -1) {
if (idx[to] == -1) {
update(to, d + 1);
} else {
int watchman_this_move = watchman_at(d + 1, idx[to]);
if (watchman_this_move == to) {
update(to, d + 2);
} else {
update(to, d + 1);
}
int watchman_passes = when_watchman(d + 1, to);
update(to, watchman_passes + 1);
}
} else if (idx[to] == -1) {
update(to, d + 1);
} else if (idx[to] == idx[i]) {
if (watchman_at(d, idx[i]) == to && watchman_at(d + 1, idx[i]) == i || watchman_at(d + 1, idx[i]) == to) {
continue;
}
update(to, d + 1);
} else {
for (int cur_d : {d, d + sz(v[idx[i]])}) {
int can_stay_until = when_watchman(cur_d, i);
if (watchman_at(cur_d + 1, idx[to]) == to) {
if (can_stay_until > cur_d + 1) {
update(to, cur_d + 2);
}
} else {
update(to, cur_d + 1);
}
int watchman_passes = when_watchman(cur_d + 1, to);
if (can_stay_until > watchman_passes) {
update(to, watchman_passes + 1);
}
}
}
}
}
if (dist[n - 1] == INF) {
cout << "impossible\n";
} else {
cout << dist[n - 1] << '\n';
}
}
int main() {
#ifdef LOCAL
freopen("../in.txt", "r", stdin);
//freopen("../out.txt", "w", stdout);
#else
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
#endif
solve();
return 0;
}
