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:
    list1=input().split('"')
    if list1[0]==".":
        break
    list2=input().split('"')
     
    cnt1=0
    cnt2=0
    flag=0
     
    if len(list1)!=len(list2):
        print("DIFFERENT")
    else:
        i=0
        while i<len(list1):
            if list1[i]==list2[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==0 and cnt2==1:
            print("CLOSE")
        if cnt1==len(list1):
            print("IDENTICAL")

Python: def p(A,s):
    i=0
    j=0
    s=[]
    while(len(A)>i):
        if A[i]=='"':
            list1=A.partition('"')
            s.append(list1[0])
            A=list1[2]
            i=0
            j+=1
        else:
            i+=1
            if len(A)==i:
                s.append(A)
    return s
A=input()
s1=[]
s2=[]
O=[]
while 1:
    i=0
    cnt=0
    B=input()
    s1=p(A,s1)
    s2=p(B,s2)
    l1=len(s1)
    l2=len(s2)    
    while i<l1 and i<l2:
        if s1[i]!=s2[i]:
            cnt+=1
        i+=1
    if cnt==0:
        O.append("IDENTICAL")
    elif cnt==1:
        O.append("CLOSE")
    else:
        O.append("DIFFERENT")
    A=input()
    if A==".":
        break
    
for i in range(len(O)):
    print(O[i])

Python: #16D8101014F 久留米 竜之介 Python3
#a=[]
while(True):
	i=0
	tmp=0
	a=input().split('"') 
	aL=len(a)
	b=input().split('"')
	bL=len(b)
	if aL != bL:
		print("DIFFELENT")
	else:
		while(True):
			if a[i] != b[i]:
				print("DIFFERENT")
				break
			elif i > aL-2:
				if tmp==1:
					print("CLOSE")
					break
				else:
					print("IDENTICAL")
					break
			elif a[i+1] != b[i+1]:
				if tmp==1:
					print("DIFFERENT")
					break
				else: tmp=1
			i +=2

Python: ans=[]
while 1:
    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
	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")

Python: while True:
    s1 = input()
    if s1 == ".":
        break
    s2 = input()

    listed_s1 = [[]]
    listed_s2 = [[]]
    start = 0
    now = 0
    for i in range(len(s1)):
        if s1[i] == "\"" and not start:
            listed_s1.append([])
            now += 1
            start = 1
            listed_s1[now].append(s1[i])
        elif s1[i] == "\"" and start:
            listed_s1[now].append(s1[i])
            listed_s1.append([])
            now += 1
            start = 0
        else:
            listed_s1[now].append(s1[i])

    now = 0
    for i in range(len(s2)):
        if s2[i] == "\"" and not start:
            listed_s2.append([])
            now += 1
            start = 1
            listed_s2[now].append(s2[i])
        elif s2[i] == "\"" and start:
            listed_s2[now].append(s2[i])
            listed_s2.append([])
            now += 1
            start = 0
        else:
            listed_s2[now].append(s2[i])

    fist_wrong = 0
    ans = "IDENTICAL"
    for i in range(min(len(listed_s1), len(listed_s2))):
        if listed_s1[i] != listed_s2[i]:
            if listed_s1[i][0] == "\"" and listed_s2[i][-1] == "\"" and listed_s2[i][0] == "\"" and listed_s2[i][-1] == "\"":
                if fist_wrong:
                    ans = "DIFFERENT"
                else:
                    fist_wrong = 1
                    ans = "CLOSE"

            else:
                ans = "DIFFERENT"
        if ans == "DIFFERENT":
            break
    if len(listed_s1) != len(listed_s2):
        ans = "DIFEERENT"


    print(ans)

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

    if s1 == s2:
        print("IDENTICAL")
        continue

    s2 = s2.split('"')
    s1 = s1.split('"')
    # print(s1)
    # print(s2)
    count = 0
    isTmp = False
    if s1[0] == '"' and s2[0] == '"':
        isTmp = True

    hoge = True
    for i in range(len(s1)):
        if len(s1) != len(s2):
            print("DIFFERENT")
            hoge = False
            break
        if count > 1:
            print("DIFFERENT")
            hoge = False
            break

        if not isTmp:
            if i % 2 == 0:
                if s1[i] != s2[i]:
                    print("DIFFERENT");
                    hoge = False
                    break
            if i % 2 == 1:
                if s1[i] != s2[i]:
                    count += 1
        else:
            if i+1 % 2 == 0:
                if s1[i] != s2[i]:
                    print("DIFFERENT");
                    hoge = False
                    break
            if i+1 % 2 == 1:
                if s1[i] != s2[i]:
                    count += 1

    if count == 1 and hoge:
        print("CLOSE")