/*
KAMUI!
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*/
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
#include <random>
using namespace std;
template<typename T1, typename T2> inline void chkmin(T1 &a, T2 b) {if (a > b) a = b;}
template<typename T1, typename T2> inline void chkmax(T1 &a, T2 b) {if (a < b) a = b;}
#define files(FILENAME) read(FILENAME); write(FILENAME)
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define all(c) (c).begin(), (c).end()
#define sz(c) (int)(c).size()
#define left left228
#define right right228
#define y1 y1228
#define mp make_pair
#define pb push_back
#define y2 y2228
#define rank rank228
using ll = long long;
using ld = long double;
const string FILENAME = "input";
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.tie(0);
cout.tie(0);
// read(FILENAME);
cin >> N >> M;
for (int i = 0; i < N; i++) {
r[i] = 0, t[i] = -1;
}
for (int i = 0; i < M; i++) {
int u, v;
cin >> u >> v;
u--, v--;
e[u].pb(v);
e[v].pb(u);
}
cin >> K;
L[0] = 1;
for (int i = 1; i <= K; i++) {
cin >> L[i];
for (int j = 0; j < L[i]; j++) {
int u;
cin >> u;
u--;
V[i].pb(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 < sz(e[i]); 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';
}
return 0;
}
