#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#define mi(x, y) (x = min(x, y))
#define ma(x, y) (x = max(x, y))
using namespace std;
const int NS = 250004;
int n, m;
vector<int> way[NS];
vector<int> dp[NS];
int len[NS], fir[NS], col[NS];
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m;
for(int i = 0; i < m; ++i){
int x, y;
cin >> x >> y;
--x, --y;
way[x].push_back(y);
way[y].push_back(x);
}
int k;
cin >> k;
for(int i = 0; i < k; ++i){
int x;
cin >> x;
for(int j = 0; j < x; ++j){
int y;
cin >> y;
--y;
dp[y] = vector<int>(x, (int)1e9);
len[y] = x;
col[y] = i + 1;
fir[y] = j;
}
}
for(int i = 0; i < n; ++i){
if(!(int)dp[i].size()){
dp[i] = {(int)1e9};
}
}
priority_queue<vector<int>> pq;
auto enq = [&](int x, int t){
int md = (col[x] ? t % len[x] : 0);
if((!col[x] || md != fir[x]) && t < dp[x][md]){
pq.push({-t, x});
}
};
auto gett = [&](int x, int t){
if(t <= fir[x]) return fir[x];
return ((t - fir[x] - 1) / len[x] + 1) * len[x] + fir[x];
};
enq(0, 0);
while(!pq.empty()){
int now = pq.top()[1];
int nt = -pq.top()[0];
pq.pop();
int md = (col[now] ? nt % len[now] : 0);
if(dp[now][md] == nt){
continue;
}
if(now == n - 1){
cout << nt << '\n';
return 0;
}
//cout << now + 1 << ' ' << nt << endl;
dp[now][md] = nt;
enq(now, nt + 1);
for(int i = 0; i < (int)way[now].size(); ++i){
int nxt = way[now][i];
if(!col[now] || !(col[now] == col[nxt] && fir[now] == (fir[nxt] + 1) % len[now] && fir[nxt] == nt % len[now])){
enq(nxt, nt + 1);
}
if(!col[now] && col[nxt]){
enq(nxt, gett(nxt, nt) + 1);
}
int f = 0;
if(col[now] && col[nxt] && (col[now] != col[nxt] || (fir[now] != (fir[nxt] + 1) % len[now] && fir[nxt] != (fir[now] + 1) % len[nxt]))){
int t2 = gett(nxt, nt);
int t1 = gett(now, t2);
if(t1 != t2){
enq(nxt, t2 + 1);
f = 1;
}
else{
int t3 = t1 + (len[now] * 2 - fir[now] + md) % len[now];
int t4 = gett(nxt, t3);
enq(nxt, t3 + 1);
if(gett(now, t4) != t4){
enq(nxt, t4 + 1);
}
}
}
if(!col[now] || !col[nxt] || f){
swap(way[now][i], way[now].back());
way[now].pop_back();
--i;
}
}
}
cout << "impossible\n";
return 0;
}
