#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
int cnt;
struct node{
    char data[15];
    int len;
}Node[10];
bool decode(){
    bool flag;
    int k;
    for(int i=0;i<cnt-1;i++){
        for(int j=i+1;j<cnt;j++){
            flag = false;
            if(Node[i].len>Node[j].len){
                for(k=0;k<Node[j].len;k++){
                    if(Node[i].data[k]!=Node[j].data[k]){
                        break;
                    }
                }
                if(k==Node[j].len){
                    flag = true;
                }
            }
            if(flag)return false;
            flag = false;
            if(Node[i].len<Node[j].len){
                for(k=0;k<Node[i].len;k++){
                    if(Node[i].data[k]!=Node[j].data[k]){
                        break;
                    }
                }
                if(k==Node[i].len){
                    flag = true;
                }
            }
            if(flag)return false;
        }
    }
    return true;
}
int main(){
    cnt = 0;
    char ch[15];
    int num = 1;
    while(scanf("%s",ch)==1){
        if(ch[0]=='9'){
            if(decode())printf("Set %d is immediately decodable\n",num);
            else    printf("Set %d is not immediately decodable\n",num);
            cnt = 0;
            num++;
        }
        strcpy(Node[cnt].data,ch);
        Node[cnt].len = strlen(ch);
        cnt++;
    }
    return 0;
}