#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ii pair<int,int>
#define iii pair<int,ii>
#define fi first
#define se second
#define endl '\n'
#define puf push_front
#define pof pop_front
#define pub push_back
#define pob pop_back
#define rep(x,s,e) for (auto x=s-(s>e);x!=e-(s>e);(s<e)?x++:x--)
#define all(x) (x).begin(),(x).end()
#define sz(x) (int) (x).size()
int n,m,k;
vector<ii> edges;
vector<int> w[250005]; //period is implicit here
vector<int> al[250005];
int id[250005]; //which watchmen
int bad[250005]; //when the watchmen comes
int ped[250005];
vector<ii> dial[1000005];
void read(int &x){
x=0;
char ch=getchar_unlocked();
while (ch&16){
x=(x<<3)+(x<<1)+(ch&15);
ch=getchar_unlocked();
}
}
int fix(int i,int j){
i%=j;
if (i<0) i+=j;
return i;
}
void upd(int k,int i,int j){
if (w[i][j]>k){
w[i][j]=k;
//pq.push(iii(k,ii(i,j)));
if (k>1000000) return;
dial[k].pub(ii(i,j));
}
}
int main(){
cin.tie(0);
cout.tie(0);
cin.sync_with_stdio(false);
read(n),read(m);
int a,b;
rep(x,0,m){
read(a),read(b);
al[a].pub(b);
al[b].pub(a);
}
memset(ped,-1,sizeof(ped));
memset(id,-1,sizeof(id));
memset(bad,-1,sizeof(bad));
read(k);
rep(x,0,k){
read(a);
vector<int> path;
rep(y,0,a){
read(b);
path.pub(b);
bad[b]=y;
id[b]=x;
ped[b]=a;
}
}
rep(x,1,n+1){
if (ped[x]==-1) w[x].pub(1e9);
else{
rep(y,0,ped[x]) w[x].pub(1e9);
}
}
upd(0,1,0);
int weight=0;
while (weight<1000000){
if (dial[weight].empty()){
weight++;
continue;
}
int n1,n2;
tie(n1,n2)=dial[weight].back();
dial[weight].pob();
if (w[n1][n2]!=weight) continue;
if (ped[n1]!=-1 && weight%ped[n1]==bad[n1]) continue;
//same position as watchmen
if (n1==n){
cout<<weight<<endl;
return 0;
}
//cout<<weight<<" "<<n1<<" "<<n2<<" "<<ped[n1]<<" "<<bad[n1]<<endl;
for (int x=0;x<sz(al[n1]);x++){
auto it=al[n1][x];
if (ped[it]==-1){
//normal dijkstra into node without period
int ww=weight;
if (n1<=n) ww++;
upd(ww,it,0);
//delete the edge
swap(al[n1][x],al[n1].back());
al[n1].pob();
x--;
}
else if (ped[n1]==-1 && ped[it]!=-1){
//node without period into node with period
int ww=weight+1;
upd(ww,it,ww%ped[it]);
//also need one that lands immediately after watchmen pass
ww=weight+fix(bad[it]-weight,ped[it])+1;
upd(ww,it,ww%ped[it]);
}
else if (id[n1]==id[it]){
//same watchmen
int ww=weight+1;
if ((bad[it]+1)%ped[it]==bad[n1] && ww%ped[it]==bad[n1]) continue;
upd(ww,it,ww%ped[it]);
}
else{
//different watchmen
//time that watchmen on other side steps on it
int tt=weight+fix(bad[it]-weight,ped[it]);
if (tt%ped[n1]==bad[n1]){ //cannot come back to our side
upd(weight+1,it,weight%ped[it]);
upd(weight+1+ped[n1],it,(weight+1+ped[n1])%ped[it]);
tt=(weight+ped[n1])+fix(bad[it]-(weight+ped[n1]),ped[it]);
if (tt%ped[n1]!=bad[n1]) upd(tt+1,it,(tt+1)%ped[it]);
}
else{ //ok we can update all it
upd(weight+1,it,weight%ped[it]);
upd(tt+1,it,(tt+1)%ped[it]);
//delete the edge
swap(al[n1][x],al[n1].back());
al[n1].pob();
x--;
}
}
}
if (ped[n1]!=-1){
upd(weight+1,n1,(n2+1)%ped[n1]);
}
}
/*
rep(x,1,IDX){
cout<<x<<": ";
for (auto &it:w[x]) cout<<it<<" "; cout<<endl;
}
//*/
cout<<"impossible"<<endl;
}
