#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include <cmath>

 #include<stack>

 #include<vector>

 #include<map>

 #include<set>

 #include<queue>

 #include<algorithm>

 using namespace std;

 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)

 typedef long long LL;

 const int INF = (<<)-;

 const int mod=;

 const int maxn=;

 int d[maxn][maxn],rute[maxn],vis[maxn];

 int en,n,ans;

 void dfs(int x,int cnt){

     if(x==en){

         printf("");

         for(int i=;i<cnt-;i++) printf(" %d",rute[i]);

         printf(" %d\n",en);

         ans++;

         return;

     }

     for(int i=;i<=n;i++){

         if(!vis[i]&&d[x][i]==&&d[i][en]!=INF){            

             rute[cnt]=i;

             vis[i]=;

             dfs(i,cnt+);

             vis[i]=;

         }

     }

 }

 int main(){

     int kase=;

     while(scanf("%d",&en)!=EOF){

         int u,v;

         n=-;

         for(int i=;i<=;i++){

             for(int j=;j<=;j++) {

                 d[i][j]=INF;

             }

         }

         while(scanf("%d %d",&u,&v)&&(u||v)){

             d[u][v]=d[v][u]=;

             n=max(max(u,v),n);//找出这张图里面最大的点的标号

         }

         for(int k=;k<=n;k++)

          for(int i=;i<=n;i++)

           for(int j=;j<=n;j++)

           d[i][j]=min(d[i][j],d[i][k]+d[k][j]);

           ans=;

           memset(vis,,sizeof(vis));

           printf("CASE %d:\n", ++kase);

           dfs(,);

           printf("There are %d routes from the firestation to streetcorner %d.\n", ans, en);

     }

     return ;

 }