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>
#include<stdio.h>
#include<cstdio>
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 <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
const int INF=INT_MAX,MOD=1e9+7;

int main(){
    string s1,s2;
    while(cin>>s1>>s2&&s1!="."){
        if(s1==s2){
            cout<<"IDENTICAL"<<endl;
            continue;
        }
        int i=0,j=0,cnt=0;
        int n=s1.size(),m=s2.size();
        int mark1=0,mark2=0; //å¼•ç”¨ç¬¦
        while(1){
            string a1,a2;
            while(1){
                if(s1[i]=='"'||i>=n){
                    mark1++;
                    i++; break;
                }
                else a1+=s1[i];
                i++;
            }
            while(1){
                if(s2[j]=='"'||j>=m){
                    mark2++;
                    j++; break;
                }
                else a2+=s2[j];
                j++;
            }
            //cout<<a1<<" "<<a2<<endl;
            if(a1!=a2&&mark1%2) cnt+=100;
            else if(a1!=a2) cnt++;
            if(i>=n&&j>=m) break;
        }
        if(mark1==mark2&&cnt==1) cout<<"CLOSE"<<endl;
        else cout<<"DIFFERENT"<<endl;
        //cout<<cnt<<endl;
    }
    return 0;
}

C++: #include<bits/stdc++.h> 
#define LL long long
#define MOD 1e9+7
#define pi acos(-1.0)
#define ULL unsigned long long
#define mem_1(str) memset(str,-1,sizeof(str))
#define mem0(str) memset(str,0,sizeof(str))
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
using namespace std;
const int maxn = 110;
const int INF = 0x3f3f3f3f;
char str1[1000],str2[1000];
int main()
{
	int i;
	while(scanf("%s",str1))
	{
		if(str1[1]=='\0'&&str1[0]=='.') break;
		else 
		{
			int flag=0,flag2=0;
			int q=0;
			scanf("%s",str2);
			for(i=0;str1[i]!='\0';i++,q++)
			{
				if(str1[i]==str2[q])
				{
					if(str1[i]=='"')
					{
						i++;q++;
							while(str1[i]!='"')
						{
							if(str1[i]!=str2[q]) 
							{
								flag++;
								break;
							}
							q++;
							i++;
						}
						if(str1[i]=='"'&&str2[q]!='"')
							flag++;
						while(str2[q]!='"')
							{
								q++;
							}
						while(str1[i]!='"')
						{
							i++;
						}
						
						
				    }		
				}
				else if(str2[q]=='\0') break;
				else 
				{
					flag2=1;
					break;
				}
			}
			if(str1[i]=='\0'&&str2[q]!='\0'||str1[i]!='\0'&&str2[q]=='\0')
			{
				printf("DIFFERENT\n");
			}
			else if(flag==1&&flag2==0)
			{
				printf("CLOSE\n");
			}
			else if(flag>1||flag2==1)
			{
				printf("DIFFERENT\n");
			}
			else
			{
				printf("IDENTICAL\n");
			}
		}
		mem0(str1);
		mem0(str2);
	}
	return 0;
}