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('"')
	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: def f(S):
    S_not_in_q = []
    S_in_q = []
    tmp = ''
    i = 0
    while i < len(S):
        if S[i] == '"':
            if tmp != '':
                S_not_in_q.append(tmp)
            tmp = ''
            i += 1
            while S[i] != '"':
                tmp += S[i]
                i += 1
            else:
                S_in_q.append(tmp)
                tmp = ''
                i += 1
        else:
            tmp += S[i]
            i += 1
    else:
        if tmp != '':
            S_not_in_q.append(tmp)
    return S_not_in_q, S_in_q
    
while True:
    S1 = input()
    if S1 == '.':
        break
    S2 = input()

    if (S1 == S2):
        print('IDENTICAL')
        continue

    S1_not_in_q, S1_in_q = f(S1)
    S2_not_in_q, S2_in_q = f(S2)

    if (S1_not_in_q != S2_not_in_q):
        print('DIFFERENT')
        continue
    else:
        if len(S1_in_q) != len(S2_in_q):
            print('DIFFERENT')
            continue
        else:
            count = 0
            for i in range(len(S1_in_q)):
                if S1_in_q[i] != S2_in_q[i]:
                    count += 1
            if count < 2:
                print("CLOSE")
                continue
            else:
                print("DIFFERENT")
                continue

Python: def testcase_ends():
    s = input()
    if s == '.':
        return True

    t = input()

    if s == t:
        print('IDENTICAL')
        return False

    s0 = s.split('"')[0::2]
    s1 = s.split('"')[1::2]
    t0 = t.split('"')[0::2]
    t1 = t.split('"')[1::2]

    if s0 != t0:
        print('DIFFERENT')
        return False

    if len(s1) != len(t1):
        print('DIFFERENT')
        return False

    if len([(ss, tt) for ss, tt in zip(s1, t1) if ss != tt]) == 1:
        print('CLOSE')
    else:
        print('DIFFERENT')

    return False

def main():
    while not testcase_ends():
        pass

main()

Python: def check(str1,str2):
    if not(len(str1)==len(str2)):
        return False 
    for i in range(len(str1)):
        if not(str1[i]==str2[i]):
            return False
    return True


def solve(s1,s2):
    #print(len(s1),len(s2))
    if not(len(s1) == len(s2)):
        print("DIFFERENT")
        return
    flag = True
    for i in range(len(s1)):
        if not(check(s1[i],s2[i])):
            if i%2==1:
                if flag:
                    flag = False
                else:
                    print("DIFFERENT")
                    return
            else:
                print("DIFFERENT")
                return
    if flag:
        print("IDENTICAL")
    else:
        print("CLOSE")
        
    return


while True:
    s1=input().split('"')
    if s1[0] == '.':
        break
    s2 = input().split('"')
    solve(s1,s2)

Python: results=[]
while True:
    a=input().split("\"")
    if a[0]==".":
        break
    b=input().split("\"")
    count1=0
    count2=0
    if len(a) != len(b):
        results.append(2)
    else:
        for i in range(len(a)):
            if(i%2==1):
                for k,l in zip(a[i],b[i]):
                    if k is None and l is None:
                        pass
                    elif k is None and l is not None:
                        count1+=1
                    elif k is not None and l is None:
                        count1+=1
                    elif(k!=l):
                        count1+=1
            else:
                for k,l in zip(a[i],b[i]):
                    if k is None and l is None:
                        pass
                    elif k is None and l is not None:
                        count2+=1
                    elif k is not None and l is None:
                        count2+=1
                    if(k!=l):
                        count2+=1
            print("a[{}]\n{}".format(i,a[i]))
            print("b[{}]\n{}".format(i,b[i]))
            print("count1:{}".format(count1))
            print("count2:{}".format(count2))
        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")