#include <iostream>
#include <cstdio>
#include <string.h>
using namespace std;
int is_prefix(char *a,char *b)
{
int m,n,i;
m=strlen(a),n=strlen(b);
char *longer=m>=n?a:b;
char *shorter=m<n?a:b;
m=strlen(longer),n=strlen(shorter);
for(i=0;i<n;i++)
if(shorter[i]!=longer[i])
break;
return i==n?1:0;
}
int main()
{
//freopen("Input.txt","r",stdin);
//freopen("Output.txt","w",stdout);
char s[10][10];
memset(s,0,sizeof(s));
int i=0,j,k,count=0,flag;
while(scanf("%s",s[i])!=EOF)
{
if(s[i][0]!='9')
{
i++;
continue;
}
else
{
count++;
flag=0;
for(j=1;j<i;j++)
{
for(k=0;k<j;k++)
if(is_prefix(s[j],s[k]))
{
flag=1;
break;
}
if(flag)
{
cout<<"Set "<<count<<" is not immediately decodable"<<endl;
break;
}
}
if(!flag)
cout<<"Set "<<count<<" is immediately decodable"<<endl;
memset(s,0,sizeof(s));
i=0;
}
}
return 0;
}