#include <fstream>

using namespace std;

ifstream fin("lantminim.in");
ofstream fout("lantminim.out");

int a[101][101],c[101],t[101],d[101],viz[101];
int n,p,q,st,dr;

void Citire()
{
    int x,y,i;
    fin >> n >> p >> q;
    while(fin >> x >> y)
    {
        a[x][y] = a[y][x] = 1;
    }
}

void BFS(int p, int q)
{
    int i,k;
    st = dr = 1;
    viz[p] = 1;
    c[1] = p;
    t[p] = 0;
    d[p] = 1;
    while(st <= dr)
    {
        k = c[st];
        st++;
        for(i = 1; i<= n; i++)
            if(a[k][i] and !viz[i])
        {
            c[++dr] = i;
            viz[i] = 1;
            t[i] = k;
            d[i] = d[k] + 1;
        }
    }
}

void Afis(int p)
{
    if(p)
    {
        Afis(t[p]);
        fout << p <<" ";
    }
}
int main()
{
    Citire();
    BFS(p,q);
    fout << d[q]<<"\n";
    Afis(q);
    return 0;
}