#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()
priority_queue<pair<ll,pll>, vector<pair<ll,pll>>, greater<pair<ll,pll>>> pq;
vvl ds;
void pp(pair<ll,pll> a){
if(a.s.f==-1){
if(ds[a.s.s][0]>a.f){
pq.push(a);
ds[a.s.s][0]=a.f;
}
}
else{
if(ds[a.s.s][a.s.f]>a.f){
pq.push(a);
ds[a.s.s][a.s.f]=a.f;
}
}
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(NULL);
ll n, m, a, b, l, k;
cin >> n >> m;
vvl g(n);
vll ln(n), id(n), ma(n);
for(ll i = 0; i < m; ++i){
cin >> a >> b;a--;b--;
g[a].pb(b);
g[b].pb(a);
}
ds = vvl(n, vll(1, 1e11));
cin >> k;
for(ll i = 1; i <= k; ++i){
cin >> l;
for(ll j = 0; j < l; ++j){
cin >> a;a--;
ln[a]=l;
id[a]=j;
ma[a]=i;
ds[a]=vll(l, 1e11);
g[a].pb(a);
}
}
pp({0, {-1,0}});
while(!pq.empty()){
auto [t, e] = pq.top();
pq.pop();
auto [r, cr] = e;
if(r==-1){
if(t>ds[cr][0])continue;
ds[cr][0]=t;
for(ll i:g[cr]){
if(ma[i]==0){
pp({t+1, {-1, i}});
}
else{
if((t+1)%ln[i]!=id[i])pp({t+1, {(t+1)%ln[i], i}});
pp({t+1+((id[i]-t)%ln[i]+ln[i])%ln[i], {(id[i]+1)%ln[i], i}});
}
}
}
else{
if(t>ds[cr][r])continue;
ds[cr][r]=t;
for(ll i:g[cr]){
if(ma[i]==0){
pp({t+1, {-1, i}});
}
else if(ma[i]!=ma[cr]){
if((t+1)%ln[i]!=id[i])pp({t+1, {(t+1)%ln[i], i}});
}
else{
if((t+1)%ln[i]==id[i])continue;
if(t%ln[i]==id[i] && (t+1)%ln[cr]==id[cr])continue;
pp({t+1, {(t+1)%ln[i], i}});
}
}
g[cr].clear();
g[cr].pb(cr);
}
}
ll ans = 1e11;
for(ll i:ds[n-1])ans = min(ans, i);
if(ans!=1e11)cout << ans;
else cout << "impossible";
}
