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)
}

C++: #include<iostream>
#include<vector>
#include<string>
int main(){
	int i,j,k,l,m,lim,flag1=0,flag2,flag3,flag4,count=0,x,scou1=0,scou2=0;
	std::string s1;
	std::string s2;
	std::vector<std::string> ans;
	char str1[200],str2[200];
	while(1){
		gets(str1);
		i=0;
		while(str1[i]!=NULL){
			s1.push_back(str1[i]);
			i++;
		}
//		std::cout<<s1<<"\n";
		if(s1=="."){
//			std::cout<<s1<<"\n";
			break;
		}
		gets(str2);
		k=0;
		while(str2[k]!=NULL){
			s2.push_back(str2[k]);
			k++;
		}
//		std::cout<<s2<<"\n";
//		std::cout<<i<<"\n";
		scou1=0;
		scou2=0;
		flag1=0;
		flag2=0;
		flag3=0;
		flag4=0;
		if(i<k){
			l=i;
			lim=k;
		}else{
			l=k;
			lim=i;
		}
		j=0;
		m=0;
		for(int z=0;z<l;z++){
			if(s1[j]=='"'){
				scou1++;
			}
			if(s2[m]=='"'){
				scou2++;
			}
			
			std::cout<<s1[j]<<" "<<s2[m]<<"\n";
			
			if(s1[j]!=s2[m]){
				if(flag4==1){
					flag2=1;
					break;
				}
				if(scou1%2==1&&scou2%2==1){
					flag2=2;
					flag3=1;
				}else if(scou1%2==1){
					while(s1[j]!='"'){
						j++;
					}
					scou1++;
					flag2=2;
					flag3=1;
				}else if(scou2%2==1){
					while(s2[m]!='"'){
						m++;
					}
					scou2++;
					flag2=2;
					flag3=1;
				}else{
					flag2=1;
					break;
				}
				
			}
			
			if(flag3==1&&scou1%2==0&&scou2%2==0){
					flag4=1;
					std::cout<<"tutgihanai\n";
				}
			
			j++;
			m++;
		}
		
		if(m<lim&&j<lim){
			flag2=1;
		}
		
//		std::cout<<m<<j<<lim<<"\n";
		
		if(flag2==0){
			ans.push_back("IDENTICAL");
		}else if(flag2==1){
			ans.push_back("DEFFERENT");
		}else{
			ans.push_back("CLOSE");
		}
		std::cout<<ans[count]<<"\n";
		
		count++;
		s1.erase(s1.begin(),s1.end());
		s2.erase(s2.begin(),s2.end());
	}
	
	for(int j=0;j<count;j++){
		std::cout<<ans[j]<<"\n";
	}
	
	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int n,m,l;
string s1, s2;
void input() {
	cin >> s1;
	if (s1 == ".")return;
	cin >> s2;
}
void output() {
	cout << endl;
}
void prep() {
	n = s1.length();
	m = s2.length();
	s1 = s1 + "$";
	s2 = s2 + "$";
}
void solve() {
	int i = 0;
	int j = 0;
	int h = 1;
	int cnt = 0;
	while (i+j<m+n-1) {
		h = 1 - h;
		string c1 = "";
		string c2 = "";
		while (i < n) {
			c1=c1+s1[i];
			if (s1[i] == '"')break;
			i++;
		}
		i++;
		while (j < m) {
			c2=c2+s2[j];
			if (s2[j] == '"')break;
			j++;
		}
		j++;
		if (c1._Equal(c2) == false) {
			if (h == 0) {
				cout << "DIFFERENT";
				return;
			}
			cnt++ ;
			if (cnt == 2) {
				cout << "DIFFERENT";
				return;
			}
		}
	}
	if (cnt == 0)cout << "IDENTICAL"; else cout << "CLOSE";
}
int main() {
	while (true) {
		input();
		if (s1 == ".")break;
		prep();
		solve();
		output();
	}
}

C++: // 2017/12/11 Tazoe

#include <iostream>
#include <string>
using namespace std;

int main()
{
	while(true){
		string s1;
		cin >> s1;

		if(s1==".")
			break;

		string s2;
		cin >> s2;

		if(s1==s2){				// ?????¨?????????????????°
			cout << "IDENTICAL" << endl;
			continue;
		}

		string t1 = s1;
		string t2 = s2;

		while(true){
			size_t d1b = t1.find('\"');	// t1???"????§???????
			if(d1b==string::npos)
				break;
			t1.replace(d1b, 1, "@");

			size_t d1e = t1.find('\"');	// t1???"????????????
			t1.replace(d1e, 1, "@");

			size_t d2b = t2.find('\"');	// t2???"????§???????
			if(d2b==string::npos)
				break;
			t2.replace(d2b, 1, "@");

			size_t d2e = t2.find('\"');	// t2???"????????????
			t2.replace(d2e, 1, "@");

			string u1 = s1;
			u1.replace(d1b+1, d1e-d1b-1, "");	// u1?????????????????°?????????
			string u2 = s2;
			u2.replace(d2b+1, d2e-d2b-1, "");	// u2?????????????????°?????????

			if(u1==u2){
				t1 = u1;
				t2 = u2;
				break;
			}
		}

		if(t1==t2){				// ?????????????????°??????????????°
			cout << "CLOSE" << endl;
		}
		else{					// ????????\???
			cout << "DIFFERENT" << endl;
		}
	}

	return 0;
}

C++: #include"bits/stdc++.h"
using namespace std;

int main() {
	string s1, s2;
st:;
	cin >> s1;
	while (s1 != ".") {
		cin >> s2;

		bool f = false; // trueなら""中
		int i1, i2;
		i1 = i2 = 0; // 次に見る文字
		int n1 = s1.length();
		int n2 = s2.length();
		int count_diff = 0;
		
		while (true) {
			if (!f) {
				if (s1[i1] != s2[i2]) {
					cout << "DIFFERENT" << endl; // ""外で対応する文字が違えばDIFFERENT
					goto st;
				}
				if (s1[i1] == '"')
					f = true;
				i1++; i2++;
			}
			else {
				string str1 = "";
				string str2 = "";
				while (s1[i1] != '"') {
					str1 += s1[i1];
					i1++;
				}
				i1++;
				while (s2[i2] != '"') {
					str2 += s2[i2];
					i2++;
				}
				i2++;
				if (str1 != str2) {
					count_diff++;
				}
				f = false;
			}
			if (i1 == n1 && i2 == n2)
				break;
			if (i1 == n1 && i2 != n2) {
				cout << "DIFFERENT" << endl;
				goto st;
			}
			if (i1 != n1 && i2 == n2) {
				cout << "DIFFERENT" << endl;
				goto st;
			}
		}

		if (count_diff == 0)
			cout << "IDENTICAL" << endl;
		if (count_diff == 1)
			cout << "CLOSE" << endl;
		if (count_diff > 1)
			cout << "DIFFERENT" << endl;

		cin >> s1;
	}
	return 0;
}