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: from functools import lru_cache
ans = ['IDENTICAL', 'DIFFERENT', 'CLOSE']

def compare(s1,s2):
    if s1 == s2:
        return 0
 
    l1,l2 = s1.split('"'),s2.split('"')
    if len(l1) != len(l2):
        return 1
 
    cnt = 0
    for i in range(len(l1)):
        if i%2 == 0:
            if l1[i] != l2[i]:
                return 1
        else:
            if l1[i] != l2[i]:
                cnt += 1
            if cnt > 1:
                return 1
    return 2

while True:
    str1 = input()
    if str1 == ".":
        break
    str2 = input()
    print(ans[compare(str1,str2)])

Python: while 1:
    s1 = input().split('"')
    if s1 == ['.']:
        break
    s2 = input().split('"')
    if len(s1) != len(s2):
        print("DIFFERENT")
        continue
    r = [0]*2
    for i in range(len(s1)):
        if s1[i] != s2[i]:
            r[i%2] += 1
    if [0,1]<r:
        print("DIFFERENT")
    else:
        print(["IDENTICAL","CLOSE"][r[1]])

Python: 
while 1:
    key = 0
    s1 = input()
    if s1 == '.':
        break
    s2 = input()
    if len(s1) == len(s2):
        for i in range(len(s1)):
            if s1[i] != s2[i]:
                key += 1
            if key >= 2:
                output.append('DIFFERENT')
                break
        if key == 0:
            output.append('IDENTICAL')
        elif key == 1:
            output.append('CLOSE')

    else:
        if len(s1) > len(s2):
            d = len(s1) - len(s2)
            if d >= 2:
                output.append('DIFFERENT')
                break
            elif d == 1:
                output.append('DIFFERENT')
                break
        else:
            d = len(s2) - len(s1)
            if d >= 2:
                output.append('DIFFERENT')
                break
            elif d == 1:
                output.append('DIFFERENT')
                break


for i in range(len(output)):
    print(output[i])

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

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

Python: def vals(arr):
    even = True
    res = [[], []]
    tmp = []
    for e in arr:
        if e == "\"":
            even = not even
            res[even].append(tmp)
            tmp = []
            continue
        tmp.append(e)
    even = not even
    res[even].append(tmp)
    return res


while True:
    str1 = input()
    if str1 == ".":
        break
    a = vals(str1)
    b = vals(input())
    print(a)
    print(b)
    res = 0
    for (x, y) in zip(a[0], b[0]):
        if x != y:
            res = 2
            break
    if res == 0:
        for (a, b) in zip(a[1], b[1]):
            if a != b:
                if res == 1:
                    break
                res += 1
    if res == 0:
        print("IDENTICAL")
    elif res == 1:
        print("CLOSE")
    else:
        print("DIFFERENT")

Python: #16D8103010K Ko Okasaki
#1617

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: def main(s):
	if s == ".":
		return False
	ss = input()
	diffc = 0
	sl = s.split("\"")
	ssl = ss.split("\"")
	if len(sl) != len(ssl):
		print("DIFFERENT")
		return True
	for i in range(len(sl)):
		if i % 2 == 0:
			if sl[i] != ssl[i]:
				print("DIFFERENT")
				return True
		else:
			if sl[i] != ssl[i]:
				diffc += 1
	if diffc == 0:
		print("IDENTICAL")
	elif diffc == 1:
		print("CLOSE")
	else:
		print("DIFFERENT")
	return True


while main(input()):
	pass

Python: A=[]
while True:	
	a=input().split('"')
	if a[0]==".":
		break
	b=input().split('"')
	
	cnt=0

	if len(a)!=len(b):
		A.append(-1)
	else:
		for i in range(len(a)):
			if(a[i]==b[i]):
				pass
			else:
				cnt+=1
		print(cnt)
		if cnt>=2:
			A.append(-1)
		if cnt==1:
			A.append(0)
		if cnt==0:
			A.append(1)

A.reverse()
#print(A)
for i in range(len(A)):
	tmp=A.pop()
	if tmp==-1:
		print("DIFFERENT")
	elif tmp==0:
		print("CLOSE")
	else:
		print("IDENTICAL")

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