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: #!/usr/bin/env python3
# -*- coding: utf-8 -*-
import re

def rdp_connect() -> bool:
    global s1, s2
    s1 = input()
    if s1 == '.':
        return False
    s2 = input()
    return True

def rdp_token(s: str):
    res = []
    while s:
        match = re.match(r'[a-zA-Z0-9;]+', s)
        if match:
            res.append(s[:match.end()])
            s = s[match.end():]
            continue
        match = re.match(r'"[^"]*"', s)
        if match:
            res.append(s[:match.end()-1])
            s = s[match.end():]
            continue
        break
    return res

def rdp_check() -> bool:
    l1 = rdp_token(s1)
    l2 = rdp_token(s2)
    if len(l1) != len(l2):
        return False
    flag = True
    for t1, t2 in zip(l1, l2):
        if t1 == t2:
            continue
        if t1[0] == t2[0] == '"' and flag:
            flag = False
        else:
            return False
    return True

if __name__ == '__main__':
    while rdp_connect():
        if s1 == s2:
            print('IDENTICAL')
        elif rdp_check():
            print('CLOSE')
        else:
            print('DIFFERENT')

Python: #16D8101014F 久留米 竜之介 Python3
#a=[]
while(True):
	i=0
	tmp=0
	a=input().split('"') 
	aL=a.len()
	b=input().split('"')
	bL=b.len()
	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: 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
			if cnt==2:
				A.append(-1)
		if cnt==1:
			A.append(0)
		if cnt==0:
			A.append(1)

A.reverse()
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 is '.':
        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:
	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==0 and cnt2==1:
			print("CLOSE")
		if cnt1==len(s1):
			print("IDENTICAL")

Python: def solve(s1,s2):
    if s1 == s2:
        return 0

    l1,l2 = s1.split('"'),s2.split('"')
    if len(l1) != len(l2):
        return 1

    ct = 0
    for i in range(len(l1)):
        if i%2 == 0:
            if l1[i] != l2[i]:
                return 1
        else:
            if l1[i] != l2[i]:
                ct += 1
            if ct > 1:
                return 1
    return 2

def main():
    ans = ['IDENTICAL', 'DIFFERENT', 'CLOSE']
    while True:
        s1 = input()
        if s1 == '.':
            return
        s2 = input()
        print(ans[solve(s1,s2)])

if __name__ == '__main__':
    main()

Python: while 1:
    list1=input().split('"')
    if len(list1)==1 and list1[0]==".":
        break
    list2=input().split('"')
     
    c1=0
    c2=0
    flag=0
     
    if len(list1)!=len(list2):
        print("DIFFERENT")
    else:
        i=0
        while i<len(list1):
            if list1[i]==list2[i]:
                c1+=1
            elif i%2==0:
                print("DIFFERENT")
                flag=1
                break
            else:
                c2+=1
                if c2>1:
                    print("DIFFERENT")
                    break
            i+=1
                 
        if flag==0 and t2==1:
            print("CLOSE")
        if c1==len(list1):
            print("IDENTICAL")

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],b[2*i]):
            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")