#include<iostream>

#include<cstdio>

#include<cstdlib>

#include<cstring>

#include<cmath>

#include<vector>

#include<queue>

#include<algorithm>

using namespace std;

const int maxl=1e+4,maxc=2,BASE='0';

struct Trie

{

 int tot,root,child[maxl][maxc];

 bool flag[maxl];

 Trie()

 	{

 	 memset(child[1],0,sizeof(child[1]));

 	 flag[1]=false;

 	 root=tot=1;

	}

 void insert(const char * str)

 	{

 	 int *cur=&root;

 	 for(const char *p=str;*p;++p)

 	 	{

 	 	 cur=&child[*cur][*p-BASE];

 	 	 if(*cur==0)

 	 	 	{

 	 	 	 *cur=++tot;

 	 	 	  memset(child[tot],0,sizeof(child[tot]));

 	 	 	  flag[tot]=false;

 	 	 	}

 	 	}

	  flag[*cur]=true;

	}

 bool query(const char *str)

 	{

 	 int *cur=&root;

 	 const char *p;

 	 for(p=str;*p&&*cur;++p)

 	 	{

 	 	 cur=&child[*cur][*p-BASE];

 	 	 if(flag[*cur]==true)return false;

		}

	 if((*cur==0))return true;

	 if(!(*p))return false;

	 	else return true;

	}

};

int main()

{

 bool flagg;

 int tott=0;

 do

 	{

	 tott++;

 	 flagg=false;

 	 Trie tr;

 	 char c[1000];

 	 bool ans=true;

 	 int len=0;

 	 while(true)

 	 	{

 	 	 char nowc=getchar();

 	 	 if(nowc==EOF)return 0;

 	 	 if(nowc=='9'){flagg=true;getchar();break;}

 	 	 if(nowc!='\n')c[len++]=nowc;

 	 	 	else

 	 	 		{

 	 	 		 c[len++]='\0';

 	 	 		 if(!tr.query(c)){ans=false;}

 	 	 		 tr.insert(c);

 	 	 		 len=0;continue;

				}

		}

	 if(ans){printf("Set %d is immediately decodable\n",tott);}

	 	else {printf("Set %d is not immediately decodable\n",tott);}

	} 	while(flagg);

 return 0;

}