#include <bits/stdc++.h>
using namespace std;
const int MAXN = 250000, MAXK = 1000, inf = 1 << 29;
int N, M, K, L[MAXK], r[MAXN], t[MAXN], c[MAXN];
vector<int> e[MAXN], V[MAXK], dp[MAXN];
int main() {
ios_base::sync_with_stdio(false);
cin >> N >> M;
for (int i = 0; i < N; i++)
r[i] = 0, t[i] = -1;
int u, v;
for (int i = 0; i < M; i++) {
cin >> u >> v, u--, v--;
e[u].push_back(v);
e[v].push_back(u);
}
cin >> K;
L[0] = 1;
for (int i = 1; i <= K; i++) {
cin >> L[i];
for (int j = 0; j < L[i]; j++) {
cin >> u, u--;
V[i].push_back(u);
r[u] = i;
t[u] = j;
}
}
for (int i = 0; i < N; i++) {
dp[i].resize(L[r[i]]);
for (int j = 0; j < L[r[i]]; j++)
dp[i][j] = inf;
}
priority_queue<tuple<int, int, int>> pq;
auto update = [&](int i, int d) {
int o = d % L[r[i]];
if (o != t[i] && d < dp[i][o])
dp[i][o] = d, pq.emplace(-d, i, o);
};
update(0, 0);
while (!pq.empty()) {
auto [d, i, o] = pq.top();
pq.pop();
d *= -1;
if (d != dp[i][o])
continue;
for (int k = 0; k < (int) e[i].size(); k++) {
int j = e[i][k];
if (!r[i] || r[j] != r[i] || (t[j] + 1) % L[r[i]] != t[i] || t[j] != o)
update(j, d + 1);
if (!r[i] && r[j])
update(j, d + 1 + (t[j] + L[r[j]] - d % L[r[j]]) % L[r[j]]);
bool re = false;
if (r[i] && r[j] && (r[j] != r[i] || ((t[j] + 1) % L[r[i]] != t[i] && (t[i] + 1) % L[r[i]] != t[j]))) {
int tnj = d + (t[j] + L[r[j]] - d % L[r[j]]) % L[r[j]];
int tnji = tnj + (t[i] + L[r[i]] - tnj % L[r[i]]) % L[r[i]];
if (tnj != tnji) {
update(j, tnj + 1);
re = true;
} else {
int nd = tnj + (o + L[r[i]] - t[i]) % L[r[i]];
update(j, nd + 1);
if (L[r[j]] % L[r[i]] != 0 && (L[r[i]] % L[r[j]] != 0 || (t[i] + L[r[i]] - o) % L[r[i]] >= L[r[j]]))
update(j, nd + 1 + (t[j] + L[r[j]] - nd % L[r[j]]) % L[r[j]]);
}
}
if (!r[i] || !r[j] || re) {
swap(e[i][k], e[i].back());
e[i].pop_back();
k--;
}
}
update(i, d + 1);
}
if (dp[N - 1][0] == inf)
cout << "impossible\n";
else
cout << dp[N - 1][0] << "\n";
}
