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++: #define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <fstream>
#include <set>
#include <utility>
#include <algorithm>
#include <queue>
#include <stack>
#include <deque>
#include <numeric>
#include <sstream>
#include <list>
#include <map>

#define rep(i,p,n) for(int i=(int)p;i<(int)n;i++)
#define repp(i,p,n) for(int i=(int)p;i>=(int)n;i--)
#define Sort(x) sort(x.begin(),x.end());
#define ll long long 
#define vi vector<int>
#define vvi vector<vector<int>>
#define vvvi <vector<vector<vector<int>>> 
#define vc vector<char> 
#define vvc vector<vector<char>>
#define vvvc vector<vector<vector<char>>> 
#define INF 2000000000

using namespace std;

int main() {
	while (1) {
		string s, t;
		vector<string> ss;
		vector<string> tt;
		int starts=0, startt = 0;
		getline(cin, s);
		if (s == ".")break;
		getline(cin, t);

		if (s == t) cout << "IDENTICAL" << endl;
		else {
			for (int i = 0; i < s.length(); i++) {
				if (s[i] == '"') {
					ss.push_back(s.substr(starts, i - starts));
					starts = i + 1;
				}
				if (i == s.length() - 1) ss.push_back(s.substr(starts, s.length()-1 - starts ));
			}

			for (int i = 0; i < t.length(); i++) {
				if (t[i] == '"') {
					tt.push_back(t.substr(startt, i - startt));
					startt = i + 1;
				}
				if (i == t.length() - 1) tt.push_back(t.substr(startt, t.length() - 1 - startt ));
			}

			int count = 0;
			for (int i = 0; i < ss.size(); i++) {
				if (ss[i] != tt[i]) {
					if (i % 2 == 0) {
						cout << "DIFFERENT" << endl;
						goto AWAY;
					}
					else count++;
				}
			}
			if (count == 1) cout << "CLOSE" << endl;
			else cout << "DIFFERENT" << endl;
		}
	AWAY:;
	}

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main()
{
  while(1){
    int count;
    string n1;
    string n2;
    vector<string> n1s(0);
    vector<string> n2s(0);
    vector<string> n1ns(0);
    vector<string> n2ns(0);
    cin>>n1;
    if(n1=="."){
      return 0;
    }
    cin>>n2;
    int l1=n1.size();
    int l2=n2.size();
   
    int start=-1;
    int end=-2;
    for(int i=0;i<l1;i++){
      if(n1[i]=='"'){
	if(start==-1){
	  start=i+1;
	  string str=n1.substr(end+2,start-end-3);
	  n1ns.push_back(str);
	}else{
	  end=i-1;
	  string str=n1.substr(start,end-start+1);
	  n1s.push_back(str);
	  start=-1;
	}
      }
    }
    if(start==-1){
      string str=n1.substr(end+2,l1-(end+2));
      n1ns.push_back(str);
    }
    start=-1;
    end=-2;
    for(int i=0;i<l2;i++){
      if(n2[i]=='"'){
	if(start==-1){
	  start=i+1;
	  string str=n2.substr(end+2,start-end-3);
	  n2ns.push_back(str);
	}else{
	  end=i-1;
	  string str=n2.substr(start,end-start+1);
	  n2s.push_back(str);
	  start=-1;
	}
      }
    }
    if(start==-1){
      string str=n2.substr(end+2,l2-(end+2));
      n2ns.push_back(str);
    }
    int s1=n1s.size();
    int s2=n2s.size();
    int ma=s1-s2;
    if(ma==0){
      count=0;
      for(int i=0;i<s1;i++){
	if(n2s[i]!=n1s[i]){
	  count++;
	}
      }      
    }else{
      count=-1;
    }
    for(int i=0;i<n1ns.size();i++){
      if(n1ns[i]!=n2ns[i]) count=-1;
    }
    if(count==1){
      cout<<"CLOSE"<<endl;
    }else if(count==0){
      cout<<"IDENTICIAL"<<endl;
    } else{
      cout<<"DIFFERENT"<<endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;

int main(){
	while(true){
		string s1;
		cin>>s1;
		if(s1=="."){
			break;
		}
		string s1;
		cin>>s1;
		if(s1==s2){
			cout<<"IDENTICAL"<<endl;
			continue;
		}
		string t1=s1;
		string t2=s2;
		while(true){
			size_t d1b=t1.find('\"');
			if(d1b==string::npos){
				break;
			}
			t1.replace(d1b,1,"@");
			size_t d1e=t1.find('\"');
			t1.replace(d1e,1,"@");

			size_t d2b=t2.find('\"');
			if(d2b==string::npos){
				break;
			}
			t2.replace(d2b,1,"@");
			size_t d2e=t2.find('\"');
			t2.replace(d2e,1,"@");

			string u1=s1;
			u1.replace(d1b+1,d1e-d1b-1,"");
			string u2=s2;
			u2.replace(d2b+1,d2e-d2b-1,"");

			if(u1==u2){
				t1=u1;
				t2=u2;
				break;
			}
		}
		if(t1==t2){
			cout<<"CLOSE"<<endl;
		}
		else{
			cout<<"DIFFERENT"<<endl;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;

int main(){
  while(true){
    string s1,s2;
    cin >> s1;
    if(s1[0]=='.')break;
    cin >> s2;
    int count=2;

    for(int i=0,j=0;true;i++,j++){
      if(s1[i]!=s2[j]){//そもそも違うコードだったら
        count=0;
        break;
      }
      if(s1[i]=='\0'||s2[j]=='\0')break;//コードが終わったら

      if(s1[i]=='\"'){//ダブルクオ見つけたら
        int m,n;
        for(m=i+1;s1[m]!='\"';m++){}
        for(n=j+1;s2[n]!='\"';n++){}
        //printf("i=%d j=%d m=%d n=%d\n",i,j,m,n);
        for(int p=i,q=j;p<=m;p++,q++){
          if(s1[p]!=s2[q]){
            count--;
            break;
          }
        }
        i=m;
        j=n;
      }
    }
    //出力
    if(count==2){
      cout<<"IDENTICAL"<<endl;
    }else if(count==1){
      cout<<"CLOSE"<<endl;
    }else{
      cout<<"DIFFERENT"<<endl;
    }
  }
}