// Start Time:
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<string>
#include<utility>

using namespace std;
#define  ll                     long long
#define  pb                     push_back
#define  pii                    pair<int,int>
#define  pll                    pair<ll,ll>
#define  ff                     first
#define  ss                     second
#define  MX                     1000000
#define  endl                   "\n"
#define  mod                    1000000007
#define  eps                    1/1000000000
#define  pi                     acos(-1.0)
#define  PQ                     priority_queue
#define  mem(a,b)               memset(a, b, sizeof(a))
#define  bug(a)                 cout<<#a<<":"<<a<<endl
#define  all(x)                 (x).begin(),(x).end()
#define  allr(x)                (x).rbegin(),(x).rend()
#define  double_print(x,a)      cout<<fixed<<setprecision(x)<<a<<endl

struct node
{
    bool endmark;
    node* next[10+1];
    node()
    {
        endmark = false;
        for(int i=0; i<10; i++)
            next[i]= NULL;
    }
} *root;

void insert(string str, int len)
{
    node* cur = root;
    for(int i=0; i<len; i++)
    {
        int id = str[i] - '0';
        if(cur->next[id] == NULL)
            cur->next[id] = new node();
        cur = cur->next[id];
    }
    cur->endmark = true;
}

bool search (string str, int len)
{
    node* cur = root;
    for(int i=0; i<len; i++)
    {
        int id = str[i] - '0';
        if(cur->endmark)
            return false;
        cur = cur->next[id];
    }
    return cur->endmark;
}

void del(node* cur)
{
    for(int i=0; i<10; i++)
        if(cur->next[i])
            del(cur->next[i]);
    delete(cur);
}

int main()
{
    //ios::sync_with_stdio(0); //cin.tie(0);

    string s;
    vector<pair<int,string>>v;
    root=new node();
    int tc=1;
    while(cin>>s)
    {
        if(s=="9")
        {
            sort(allr(v));
            int k=0;
            for(auto it:v)
            {
                if(!search(it.ss,it.ff))
                {
                    k=1;
                    break;
                }
            }

            if(k)
                cout<<"Set "<<tc<<" is not immediately decodable\n";
            else
                cout<<"Set "<<tc<<" is immediately decodable\n";
            del(root);
            v.clear();
            root=new node();
            tc++;
            continue;
        }

        int len=s.size();
        insert(s,len);
        v.pb({len,s});
    }

    return 0;
}