Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		s := io.NextLine()
		if s == "." {
			break
		}
		t := io.NextLine()
		if s == t {
			io.Println("IDENTICAL")
			continue
		}
		ss := strings.Split(s, "\"")
		tt := strings.Split(t, "\"")
		if len(ss) != len(tt) {
			io.Println("DIFFERENT")
			continue
		}
		cnt := 0
		for i := 0; i < len(ss); i++ {
			if i%2 == 0 {
				if ss[i] != tt[i] {
					cnt = -1
					break
				}
			} else {
				if ss[i] != tt[i] {
					cnt++
				}
			}
		}
		if cnt > 1 || cnt == -1 {
			io.Println("DIFFERENT")
		} else {
			io.Println("CLOSE")
		}
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

#define fi first
#define se second
#define repl(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep(i,n) repl(i,0,n)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define mmax(x,y) (x>y?x:y)
#define mmin(x,y) (x<y?x:y)
#define maxch(x,y) x=mmax(x,y)
#define minch(x,y) x=mmin(x,y)
#define uni(x) x.erase(unique(all(x)),x.end())
#define exist(x,y) (find(all(x),y)!=x.end())
#define bcnt __builtin_popcount

#define INF 1e16
#define mod 1000000007

string s[2];

int main(){
  while(1){
    cin>>s[0];
    if(s[0]==".")break;
    cin>>s[1];
    vector<string> ss[2];
    rep(k,2)for(int i=0;i<s[k].size();){
      string tmp="";
      while(i<s[k].size()&&s[k][i]!='\"'){
        tmp+=s[k][i];
        i++;
      }
      ss[k].push_back(tmp);
      i++;
    }
    if(ss[0].size()!=ss[1].size()){
      cout<<"DIFFERENT"<<endl;
    }else{
      bool ok=true;
      int cnt=0;
      rep(i,ss[0].size()){
        if(i%2==0){
          if(ss[0][i]!=ss[1][i])ok=false;
        }else{
          if(ss[0][i]!=ss[1][i])cnt++;
        }
      }
      if(ok&&cnt==0)cout<<"IDENTICAL"<<endl;
      else if(ok&&cnt==1)cout<<"CLOSE"<<endl;
      else cout<<"DIFFERENT"<<endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
string s,t;
main()
{
	while(cin>>s,s!=".")
	{
		cin>>t;
		vector<string>a,b;
		string now="";
		for(int i=0;i<s.size();i++)
		{
			if(s[i]=='"')
			{
				a.push_back(now);
				now="";
			}
			else now+=s[i];
		}
		a.push_back(now);
		now="";
		for(int i=0;i<t.size();i++)
		{
			if(t[i]=='"')
			{
				b.push_back(now);
				now="";
			}
			else now+=t[i];
		}
		b.push_back(now);
		int cnt=a.size()!=b.size()?2:0;
		for(int i=0;i<a.size();i++)
		{
			if(i>=b.size())cnt+=2;
			else
			{
				if(a[i]!=b[i])
				{
					cnt+=2-i%2;
				}
			}
		}
		cout<<(cnt?cnt>1?"DIFFERENT":"CLOSE":"IDENTICAL")<<endl;
	}
}

C++: #include<iostream>
#include<vector>
#include<string>
int main(){
	int i,j,k,l,m,lim,flag1=0,flag2,flag3,flag4,count=0,x,scou1=0,scou2=0;
	std::string s1,str1;
	std::string s2,str2;
	std::vector<std::string> ans;

	while(1){
		std::cin>>str1;

		
		i=0;
		while(str1[i]!=NULL){
			s1.push_back(str1[i]);
			i++;
		}
//		std::cout<<s1<<"\n";
		if(s1=="."){
//			std::cout<<s1<<"\n";
			break;
		}
		std::cin>>str2;
		k=0;
		while(str2[k]!=NULL){
			s2.push_back(str2[k]);
			k++;
		}
	
//		std::cout<<s2<<"\n";
//		std::cout<<i<<"\n";
		
		scou1=0;
		scou2=0;
		flag1=0;
		flag2=0;
		flag3=0;
		flag4=0;
		if(i<k){
			l=i;
			lim=k;
		}else{
			l=k;
			lim=i;
		}
		j=0;
		m=0;
		for(int z=0;z<l;z++){
			if(s1[j]=='"'){
				scou1++;
			}
			if(s2[m]=='"'){
				scou2++;
			}
			
			//std::cout<<s1[j]<<" "<<s2[m]<<"\n";
			
			if(s1[j]!=s2[m]){
				if(flag4==1){
					flag2=1;
					break;
				}
				if(scou1%2==1&&scou2%2==1){
					flag2=2;
					flag3=1;
				}else if(scou1%2==1){
					while(s1[j]!='"'){
						j++;
					}
					scou1++;
					flag2=2;
					flag3=1;
				}else if(scou2%2==1){
					while(s2[m]!='"'){
						m++;
					}
					scou2++;
					flag2=2;
					flag3=1;
				}else{
					flag2=1;
					break;
				}
				
			}
			
			if(flag3==1&&scou1%2==0&&scou2%2==0){
					flag4=1;
					//std::cout<<"tutgihanai\n";
				}
			
			j++;
			m++;
		}
		
		if(m<lim&&j<lim){
			flag2=1;
		}
		
//		std::cout<<m<<j<<lim<<"\n";
		
		if(flag2==0){
			ans.push_back("IDENTICAL");
		}else if(flag2==1){
			ans.push_back("DEFFERENT");
		}else{
			ans.push_back("CLOSE");
		}
		//std::cout<<ans[count]<<"\n";
		
		count++;
		s1.erase(s1.begin(),s1.end());
		s2.erase(s2.begin(),s2.end());
	}
	
	for(int j=0;j<count;j++){
		std::cout<<ans[j]<<"\n";
	}
	
	return 0;
}