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)
}

Python: results=[]
while True:
    a=input().split("\"")
    if a[0]==".":
        break
    b=input().split("\"")
    count1=0
    count2=0
    for i in range(int(len(a))):
        if(i%2==1):
            for k,l in zip(a[i],b[i]):
                if(k!=l):
                    count1+=1
        else:
            for k,l in zip(a[i],b[i]):
                if(k!=l):
                    count2+=1
        if len(a) != len(b):
            results.append(2)
        else:
            if count1==0 and count2==0:
                results.append(0)
            elif count1==1 and count2==0:
                results.append(1)
            else:
                results.append(2)
for i in results:
    if i==0:
        print("IDENTICAL")
    if i==1:
        print("CLOSE")
    if i==2:
        print("DIFFERENT")

Python: # -*- coding: utf-8 -*-
# python template for atcoder1
import re
import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline


def solve():
    s1 = input()[:-1]
    if s1 == ".":
        exit()
    else:
        s2 = input()[:-1]

    s1_split = s1.split('"')
    s2_split = s2.split('"')
    diff_word = []
    ans = "DIFFERENT"
    for a, b in zip(s1_split, s2_split):
        if a == b:
            continue
        else:
            diff_word.append(a)
    if len(s1_split) == len(s2_split):
        if len(diff_word) == 0:
            ans = "IDENTICAL"
        elif len(diff_word) == 1:
            pattern = '\"(.*?)\"'
            reg = re.compile(pattern)
            str_const = reg.findall(s1)
            if diff_word[0] in str_const:
                ans = "CLOSE"
    print(ans)


while True:
    solve()

Python: import sys
read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines

while True:
    s1 = input()
    if s1 == '.':
        break
    s2 = input()
    a = s1.strip().split('\"')
    b = s2.strip().split('\"')

    if len(a) != len(b):
        print("DIFFERENT")
    elif a[0::2] != b[0::2]:
        print("DIFFERENT")
    else:
        c = a[1::2]
        d = b[1::2]
        cnt = 0
        for i in range(len(c)):
            if c[i] != d[i]:
                cnt += 1
        if cnt == 0:
            print("IDENTICAL")
        elif cnt == 1:
            print("CLOSE")
        else:
            print("DIFFERENT")

Python: while 1:
	s1=input().split('"')
	if s1[0]==".":
		break
	s2=input().split('"')
	
	cnt1=0
	cnt2=0
	i=0
	
	if len(s1)!=len(s2):
		print("DIFFERENT")
	else:
		while i<len(s1):
			if s1[i]==s2[i]:
				cnt1+=1
			elif s1[i]!=s2[i] and i%2==0:
				print("DIFFERENT")
				break
			else:
				cnt2+=1
				if cnt2>1:
					print("DIFFERENT")
					break
			i+=1
				
		if cnt2==1:
			print("CLOSE")
		elif cnt1==len(s1):
			print("IDENTICAL")

Python: results=[]
while True:
    a=input().split("\"")
    if a[0]==".":
        break
    b=input().split("\"")
    count1=0
    count2=0
    for i in range(int(len(a))):
        if(i%2==1):
            for k,l in zip(a[i],b[i]):
                if(k!=l):
                    count1+=1
        else:
            for k,l in zip(a[i],b[i]):
                if(k!=l):
                    count2+=1
    if len(a) != len(b):
        results.append(2)
    else:
        if count1==0 and count2==0:
            results.append(0)
        elif count1==1 and count2==0:
            results.append(1)
        else:
            results.append(2)
for i in results:
    if i==0:
        print("IDENTICAL")
    if i==1:
        print("CLOSE")
    if i==2:
        print("DIFFERENT")

Python: s1 = list(str(input()))
while s1!= '.':
    s2 = list(str(input()))
    if s1 == s2:
        print("IDENTICAL")
    else:
        tmp1 = 0
        tmp2 = 0
        key = 0
        while tmp1 != len(s1)-1 or tmp2 != len(s2)-1:
            str1 = []
            str2 = []
            str3 = []
            str4 = []
            n1 = 0
            n2 = 0
            for i in range(tmp1, len(s1)):
                if s1[i] != '"':
                    str1.append(s1[i])
                    tmp1 = i
                if s1[i] == '"':
                    n1 = 1
                    j = i
                    for k in range(j+1, len(s1)):
                        if s1[k] == '"':
                            tmp1 = k+1
                            break
                        str3.append(s1[k])
                if n1 == 1:
                    break

            for i in range(tmp2, len(s2)):
                if s2[i] != '"':
                    str2.append(s2[i])
                    tmp2 = i
                if s2[i] == '"':
                    n2 = 1
                    j = i
                    for k in range(j+1, len(s2)):
                        if s2[k] == '"':
                            tmp2 = k+1
                            break
                        str4.append(s2[k])
                if n2 == 1:
                    break
            if str3 == str4:
                pass
            elif str3 != str4:
                key += 1
            if str1 != str2 or key >= 2:
                print("DIFFERENT")
                break

        if key == 1 and str1 == str2:
            print("CLOSE")
    s1 = list(str(input()))