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>
using namespace std;

int main(){
    string s,t;
    while(cin >> s&&s!="."){
        cin >> t;
        vector<string> v1,u1,v2,u2;
        bool flag = 0;
        string tmp;
        for(int i=0;i<s.size();i++){
            if(s[i]=='"'&&!flag){
                v1.push_back(tmp);
                flag = 1;
                tmp.clear();
            }else if(s[i]=='"'&&flag){
                u1.push_back(tmp);
                flag = 0;
                tmp.clear();
            }else{
                tmp.push_back(s[i]);
            }
        }
        v1.push_back(tmp);
        string tmp2;
        flag = 0;
        for(int i=0;i<t.size();i++){
            if(t[i]=='"'&&!flag){
                v2.push_back(tmp2);
                flag = 1;
                tmp2.clear();
            }else if(t[i]=='"'&&flag){
                u2.push_back(tmp2);
                flag = 0;
                tmp2.clear();
            }else{
                tmp2.push_back(t[i]);
            }
        }
        v2.push_back(tmp2);
        
        if(v1.size()!=v2.size()||u1.size()!=u2.size()){
            cout << "DIFFERENT" << endl;
            continue;
        }
        flag =0;
        for(int i=0;i<v1.size();i++){
            if(v1[i]!=v2[i]){
                cout <<"DIFFERENT" << endl;
                flag = 1;
                break;
            }
        }
        if(flag)continue;
        int cnt = 0;
        for(int i=0;i<u1.size();i++){
            if(u1[i]!=u2[i]){
                cnt++;
            }
        }
        if(cnt==0){
            cout << "IDENTICAL" << endl;
        }else if(cnt==1){
            cout << "CLOSE" << endl;
        }else{
            cout << "DIFFERENT" << endl;
        }

        
    }
    return 0;
}

C++: #include <iostream>
#define LENGTH 201
using namespace std;
char str1[LENGTH];
char str2[LENGTH];

int main(){
    while(true){
        int cnt = 0;
        cin >> str1;
        if(str1[0] == '.')
            break;
        cin >> str2;
        for(int i = 0;i <= LENGTH;i++){
            if(str1[i] != str2[i])
                cnt++;
        }
        if(cnt == 0)
            cout << "IDENTICAL" << endl;
        else if(cnt == 1)
            cout << "CLOSE" << endl;
        else
            cout << "DIFFERENT" << endl;
    }

    return 0;
}

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

int main() {
    string s1,s2;
    while (cin >> s1 >> s2)
    {
        if(s1==s2){
            cout << "IDENTICAL" << endl;
            continue;
        }

        vector<string> ss1(1, "");
        int cnt=0;
        bool flg1=0;
        for (int i = 0; i < s1.size(); i++)
        {
            if(flg1==0){
                if (s1.at(i)=='"'){
                    ++cnt;
                    ss1.push_back("");
                    flg1=1;
                }
                ss1.at(cnt)+=s1.at(i);
            }else{
                ss1.at(cnt)+=s1.at(i);
                if (s1.at(i)=='"'){
                    ++cnt;
                    ss1.push_back("");
                    flg1=0;
                }
            }
        }
        vector<string> ss2(1, "");
        cnt=0;
        flg1=0;
        for (int i = 0; i < s2.size(); i++)
        {
            if(flg1==0){
                if (s2.at(i)=='"'){
                    ++cnt;
                    ss2.push_back("");
                    flg1=1;
                }
                ss2.at(cnt)+=s2.at(i);
            }else{
                ss2.at(cnt)+=s2.at(i);
                if (s2.at(i)=='"'){
                    ++cnt;
                    ss2.push_back("");
                    flg1=0;
                }
            }
        }

        if(ss1.size()!=ss2.size()){
            cout << "DIFFERENT" << endl;
            continue;
        }
        bool flg=0;
        for (int i = 0; i < ss1.size(); i+=2)
        {
            if(ss1.at(i) != ss2.at(i)){
                cout << "DIFFERENT" << endl;
                flg=1;
                break;  
            }
        }
        if(flg==1) continue;

        cnt=0;
        for (int i = 1; i < ss1.size(); i+=2)
        {
            if(ss1.at(i) != ss2.at(i)){
                ++cnt;
            }
        }
        if(cnt<=1){
            cout << "CLOSE" << endl;
        }else{
            cout << "DIFFERENT" << endl;
        }
               
    }
}
//g++ -o b.exe b.cpp