#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
const int nmax=130005;
const int bmax=17;
vector< pair<int,int> > v[nmax];
vector<int> V[nmax+50005],l[nmax];
int ag[nmax],st[nmax+50005],lev[nmax],low[nmax],norm[nmax],comps[nmax+50005],viz[nmax+50005],x[nmax],y[nmax],ans[nmax+50005],nans[nmax],ap[nmax],B[nmax];
int ad[bmax][bmax],prc[(1<<16)][bmax],rep[bmax];
int n,m,u,bcc,s,e,q,found,j,nr,T1,T2,nochance,i,k,X,tip,cnt,rez,aux,nrez;
void baga(int x)
{
    if(B[x]&&B[x]!=bcc) B[x]=-1;
    else B[x]=bcc;
}
void mark(int X)
{
    l[ bcc ].push_back(st[u]);
    baga(x[st[u]]);baga(y[st[u]]);
    if(ag[ u ]){V[ n+bcc].push_back(ag[ u ]);V[ag[u]].push_back(n+bcc);ag[ u ]=0;}
    if(st[ u ]==X) {u--;return;}
    u--;
    mark(X);
}
void dfs(int x)
{
    int nod=0,et=0;
    low[x]=(1<<30);
    for(int i=0;i<v[ x ].size();i++)
    {
        nod=v[ x ][ i ].first;
        et=v[ x ][ i ].second;
        if(!lev[nod])
         {
           lev[nod]=lev[ x ]+1;if(!ap[et])st[ ++u ]=et;ap[et]=1;
           dfs(nod);
           if(low[nod]<low[x])
            low[x]=low[nod];
                if(low[nod]>=lev[ x ])
                {
                    bcc++;
                    mark(et);
                    V[n+bcc].push_back( x );
                    V[ x ].push_back(n+bcc);
                    ag[u]=x;//vezi aici
                }
        }else
        {
        if(!ap[et])st[++u]=et;ap[et]=1;
        if(lev[nod]<low[x])
          low[x]=lev[nod];
        }
      }
}
void defeseu(int x)
{
    viz[ x ]=1;
    st[ ++u ]=x;
    if(x==e)
    {
        found=1;aux=u;
        for(j=1; j<=u; j++)
            comps[j]=st[j];
        return;
    }
    for(int i=0; i<V[ x ].size(); i++)
        if((!found)&&(!viz[V[ x ][ i ]]))
            defeseu(V[ x ][ i ]);
    u--;
}
void add(int p)
{
    if(!norm[ x[p] ])
    {
         norm[ x[p] ]=++nr;
         rep[nr]=x[p];
    }
    if(!norm[ y[p] ])
    {
        norm[ y[p] ]=++nr;
        rep[nr]=y[p];
    }
    T1=norm[ x[p] ]-1;
    T2=norm[ y[p] ]-1;
    ad[T1][T2]=1;
    ad[T2][T1]=1;
}
void del(int X)
{
    norm[X]=0;
}
void reco(int state,int nod)
{
    if(prc[state][nod]==-1)
    {
        if(state!=0)ans[ ++rez ]=rep[nod+1];
        if(state!=0)
            nochance=1;
        return;
    }
    reco(state-(1<<nod),prc[state][nod]);
    ans[ ++rez ]=rep[nod+1];
}
void ham(int B,int inc,int sf)
{
     nr=0;
     for(i=0; i<l[B].size(); i++)
    {
         add(l[B][ i ]);
    }
    for(i=0; i<(1<<nr); i++)
        for(j=0; j<nr; j++)
             prc[i][j]=-1;
     prc[(1<<(norm[inc]-1))][norm[inc]-1]=0;
     for(i=0; i<(1<<nr); i++)
        for(j=0; j<nr; j++)
            if(prc[i][j]!=-1)
            {
                for(k=0; k<nr; k++)
                {
                    X=ad[ j ][k];
                    if((!(i&(1<<k)))&&X)
                    {
                        prc[(i|(1<<k))][k]=j;
                    }
                }
            }
    bool ok=0;
    if(sf==-1)
    {
        for(i=0; i<nr&&ok==0; i++)
            if(prc[(1<<nr)-1][i]!=-1)
                reco((1<<nr)-1,i),ok=1;
        if(!ok) nochance=1;
    }
    else reco((1<<nr)-1,norm[sf]-1);
     for(i=0; i<l[B].size(); i++)
    {
         del(x[l[B][ i ]]);
         del(y[l[B][ i ]]);
    }
    for(i=0; i<=nr; i++)
        for(j=0;j<=nr;j++)
         ad[i][j]=0;
}
bool in(int nod,int bico)
{
    if(bico<0) return 0;
    for(int i=0; i<l[bico].size(); i++)
        {
        if(x[l[bico][ i ]]==nod||y[l[bico][ i ]]==nod)
             return 1;
        }
    return 0;
}
void comprima()
{
    for(i=1; i<=rez; i++)
    {
        if(ans[i]!=ans[i+1])
            nans[++nrez]=ans[i];
    }
    rez=nrez;
    for(i=1; i<=nrez; i++)
        ans[i]=nans[i];
}
int main()
{
    ifstream f("santa.in");
    ofstream g("santa.out");
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x[ i ]>>y[ i ];
        v[ x[ i ] ].push_back({y[ i ],i});
        v[ y[ i ] ].push_back({x[ i ],i});
    }
    f>>s>>e>>q;
    lev[1]=1;
    dfs(s);
    for(i=1;i<=n;i++)
        if(B[i]>0)
    {
        V[i].push_back(B[i]+n);
        V[B[i]+n].push_back(i);
    }
    defeseu(s);//grija cum refolosesti stiva
    u=aux;
    if(in(q,comps[2]-n)) tip=1;
    if(in(q,comps[u-1]-n)) tip+=2;
    if(tip==0)
    {
        g<<"No chance";
        return 0;
    }
    if(tip==1)
    {
        ham(comps[ 2 ]-n,q,comps[ 3 ]);
        for(cnt=4; cnt<=u; cnt+=2)
        {
            if(cnt==u-1) ham(comps[ cnt ]-n,comps[ cnt-1 ],-1);
            else ham(comps[ cnt ]-n,comps[ cnt-1 ],comps[ cnt+1 ] );
        }
    }
    if(tip==2)
    {
        ham(comps[ u-1 ]-n,q,comps[u-2]);
        for(cnt=u-3; cnt>0; cnt-=2)
        {
            if(cnt==2) ham(comps[ cnt ]-n,comps[ cnt+1 ],-1 );
            else ham(comps[ cnt ]-n,comps[ cnt+1 ],comps[ cnt-1 ] );
        }
    }
    if(tip==3)
    {
        ham(comps[2]-n,q,-1);
        if(u>3) nochance=1;
    }
    comprima();
    if(nochance) g<<"No chance";
    else
    {
        g<<rez<<'\n';
        for(i=1; i<=rez; i++)
            g<<ans[ i ]<<' ';
    }
    return 0;
}