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: while 1:
    s1 = input().split('"')
    l1 = len(s1)
    if s1[0] == ".": break
    s2 = input().split('"')
    l2 = len(s2)
    if l1 != l2:
        print("DIFFERENT")
        continue
    i = 0
    cnt = 0
    while 1:
        if s1[i] != s2[i]:
            print("DIFFERENT")
            break
        if i > l1-2:
            if cnt == 1:
                print("CLOSE")
                break
            else:
                print("IDENTICAL")
                break
        if s1[i+1] != s2[i+1]:
            if cnt == 1:
                print("DIFFERENT")
                break
            else: cnt = 1
        i += 2

Python: results=[]
while True:
    a=input().split("\"")
    if a[0]==".":
        break
    b=input().split("\"")
    count1=0
    count2=0
    print(a)
    print(b)
    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: while True:
    s1=input().split('"')
    if s1==["."]: break
    s2=input().split('"')
    if len(s1)!=len(s2):
        print("DIFFERENT")
        continue
    else:
        cnt=0
        for i in range(len(s1)):
            if s1[i]!=s2[i]:
                cnt+=1
            else: pass
        if cnt==0:
            print("IDENTICAL")
        elif cnt==1:
            print("CLOSE")
        else: 
            print("DEFFERENT")

Python: while 1:
    s1 = input().split('"')
    l1 = len(s1)
    if s1[0] == ".": break
    s2 = input().split('"')
    l2 = len(s2)
    if l1 != l2:
        print("DIFFERENT")
        continue
    i = 0
    cnt = 0
    while 1:
        if i > l1-2:
            if cnt == 1:
                print("CLOSE")
                break
            else:
                print("IDENTICAL")
                break
        if s1[i] != s2[i]:
            print("DIFFERENT")
            break
        if s1[i+1] != s2[i+1]:
            if cnt == 1:
                print("DIFFERENT")
                break
            else: cnt = 1
        i += 2

Python: """
与えられた二つのプログラムが完全に等しければ IDENTICAL と出力せよ．
二つのプログラム中の対応する文字列定数一つだけが異なるならば CLOSE と出力せよ．
それ以外の場合，DIFFERENT と出力せよ．
"""
import re


while True:
    s1 = str(input())
    if s1 == '.':
        break
    s2 = str(input())

    moziretsuteisu_s1 = re.findall("\".*?\"", s1)
    moziretsuteisu_s2 = re.findall("\".*?\"", s2)

    new_s1 = re.sub("\".*?\"", " ", s1)
    new_s2 = re.sub("\".*?\"", " ", s2)

    cnt = 0
    if len(moziretsuteisu_s1) != len(moziretsuteisu_s2):
        cnt = 2
    else:
        for x, y in zip(moziretsuteisu_s1, moziretsuteisu_s2):
            if x != y:
                cnt += 1

    if s1 == s2:
        print("IDENTICAL")
    elif cnt == 1 and new_s1 == new_s2:
        print("CLOSE")
    else:
        print("DIFFERENT")

Python: while 1:
    s1 = input().split('"')
    l1 = len(s1)
    if s1[0] == ".": break
    s2 = input().split('"')
    l2 = len(s2)
    if l1 != l2:
        print("DIFFERENT")
        continue
    i = 0
    cnt = 0
#    print(s1,s2)
    while 1:
        if s1[i] != s2[i]:
            print("DIFFERENT")
            break
        if i > l1-2:
            if cnt == 1:
                print("CLOSE")
                break
            else:
                print("IDENTICAL")
                break
        if s1[i+1] != s2[i+1]:
            if cnt == 1:
                print("DIFFERENT")
                break
            else: cnt = 1
        i += 2

Python: results=[]
while True:
    a=input().split("\"")
    if a[0]==".":
        break
    b=input().split("\"")
    count=0
    for i in range(int(len(a)/2)):
        for k,l in zip(a[2*i+1],b[2*i+1]):
            if(k!=l):
                count+=1
    if count==0:
        results.append(0)
    elif count==1:
        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")