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<bits/stdc++.h>
using namespace std;
 
#define rep(i,m,n) for(int i = (m); i < (int)(n); i++)
#define rrep(i,m,n) for(int i=(int)(m); i>=(int)(n); i--)
#define vsort(v) sort(v.begin(), v.end());
#define rvsort(v) sort(v.begin(), v.end(),greater<int>());
#define YES cout<<"YES"<< endl
#define NO cout<<"NO"<<endl
#define Yes cout<<"Yes"<<endl
#define No cout<<"No"<<endl  
#define yes cout<<"yes"<<endl
#define no cout<<"no"<<endl
#define ret return
#define lb(v,n) lower_bound(v.begin(),v.end(),n)
#define ub(v,n) upper_bound(v.begin(),v.end(),n)
#define mae(v) max_element(v.begin(),v.end())
#define mie(v) min_element(v.begin(),v.end())
#define INF 0x7FFFFFFF
#define mod 1000000007
#define fir first
#define sec second
typedef long long ll;
////////////////////////////////////////////////////////////

vector<pair<string,bool>> hoge( string s ){
	vector<pair<string,bool>> arr;
	string tmp = "";
	bool f1 = 0;
	rep(i,0,s.size()){
		if( !f1 && s[i] == '"' ){
			f1 = 1;
			arr.push_back( make_pair(tmp,0));
			tmp = "";
		}
		else if( f1 && s[i] == '"' ){
			f1 = 0;
			arr.push_back( make_pair(tmp,1));
			tmp = "";
		}
		else{
			tmp += s[i];
		}
	}
	if( tmp.size() > 1 )
		arr.push_back( make_pair(tmp,0));
	ret arr;
}

int main(){
	while(1){
		string s1,s2;
		cin >> s1;
		if( s1 == ".") break;
		cin >> s2;
		vector<pair<string,bool>> arr1 = hoge(s1) , arr2 = hoge(s2);

		/*
		rep( i,0,arr1.size()) cout << arr1[i].fir << " " << arr1[i].sec << endl;
		rep( i,0,arr2.size()) cout << arr2[i].fir << " " << arr2[i].sec << endl;
		*/

		int cnt = 0;

		if( arr1.size() != arr2.size() ) cnt += 100;
		rep(i,0,min( arr1.size() , arr2.size() )){
			if( arr1[i].sec != arr2[i].sec ) cnt += 100;
			else if( arr1[i].fir != arr2[i].fir){
				if( arr1[i].sec == 1 )
					cnt++;
				else
					cnt += 100;
			}
		}

		if( cnt == 0 ) cout << "IDENTICAL" << endl;
		else if( cnt == 1 ) cout << "CLOSE" << endl;
		else cout << "DIFFERENT" << endl;
	}
	ret 0;
}

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,str1;
	std::string s2,str2;
	std::vector<std::string> ans;

	while(1){
		std::cin>>str1;

		
		i=0;
		while(str1[i]!=NULL){
			s1.push_back(str1[i]);
			i++;
		}
//		std::cout<<s1<<"\n";
		if(s1=="."){
//			std::cout<<s1<<"\n";
			break;
		}
		std::cin>>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){
					if(s1[j]!='"'){
						while(s1[j]!='"'){
							j++;
						}
						scou1++;
						flag2=2;
						flag3=1;
					}else{
						flag2=1;
						break;
					}
				}else if(scou2%2==1){
					if(s2[j]!='"'){
						while(s2[j]!='"'){
							j++;
						}
						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;
}