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<algorithm>
#include<numeric>
#include<vector>
#include<set>
#include <math.h>
#include <string>
#define cinf(n,x,y) for(int i=0;i<(n);i++) cin >> x[i]>>y[i];
typedef long long int ll;
const ll INF =1LL << 62;
using namespace std;
int MAX_E=1000010;
ll dp[1000010];
void split(string s, vector<string> &v){
	v.clear();
	s +='"';
	string str="";
	for(int i=0;i<s.size();i++){
		if(s[i]=='"'){
			v.push_back(str);
			str="";
		}
		else{
			str+=s[i];
		}
	}
}
int main(){
	while(1){
		string s1,s2; cin >>s1;
		if(s1==".")break;
		cin >> s2;
		if(s1==s2){
			cout << "IDENTICAL"<< endl;
		}
		else{
			vector<string> v1,v2;
			split(s1,v1);
			split(s2,v2);
			if(v1.size()!=v2.size()){
				cout << "DIFFERENT" << endl;
			}
			else{
				bool a=false;
				int cnt=0;
				for(int i=0;i<v1.size();i++){
					if(i%2==0){
						if(v1[i]!=v2[i])a=true;
					}
					else{
						if(v1[i]!=v2[i])cnt++;
					}
				}
				if(a){
					cout << "DIFFERENT" << endl;
				}
				else if(cnt>1){
					cout << "DIFFERENT" << endl;
				}
				else{
					cout << "CLOSE" << endl;
				}
			}
		}
	}
}

C++: #include<iostream>
#include<algorithm>
#include<numeric>
#include<vector>
#include <string>
using namespace std;

void split(string s, vector<string> &v){
    v.clear();
    s +='"';
    string str="";
    for(int i=0;i<s.size();i++){
        if(s[i]=='"'){
            v.push_back(str);
            str="";
        }
        else{
            str+=s[i];
        }
    }
}
int main(){
    while(1){
        string s1,s2; cin >>s1;
        if(s1==".")break;
        cin >> s2;
        if(s1==s2){
            cout << "IDENTICAL"<< endl;
        }
        else{
            vector<string> v1,v2;
            split(s1,v1);
            split(s2,v2);
            if(v1.size()!=v2.size()){
                cout << "DIFFERENT" << endl;
            }
            else{
                int cnt=0;
                for(int i=0;i<v1.size();i++){
                    if(i%2==0){
                        if(v1[i]!=v2[i]){
                            cout << "DIFFERENT" << endl;
                            continue;
                        }
                    }
                    else{
                        if(v1[i]!=v2[i])cnt++;
                    }
                }
                if(cnt>1){
                    cout << "DIFFERENT" << endl;
                }
                else{
                    cout << "CLOSE" << endl;
                }
            }
        }
    }
}

C++: #include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

void hoge(string s, string &new_s, vector<string> &vs) {
    bool in_quote = false;
    string sub_s = "";
    for (char c: s) {
        if (in_quote) {
            if (c == '"') {
                vs.emplace_back(sub_s); sub_s = "";
                in_quote = false;
            } else {
                sub_s += c;
            }
        } else {
            if (c == '"') {
                in_quote = true;
                new_s += "@";
            } else {
                new_s += c;
            }
        }
    }
}

string solve(string s, string t) {
    vector<string> vs, vt;
    string new_s, new_t;
    hoge(s, new_s, vs);
    hoge(t, new_t, vt);
    if (new_s != new_t) return "DIFFERENT";
    int cnt = 0;
    for (int i = 0; i < vs.size(); i++) {
        cnt += vs[i] != vt[i];
    }
    if (cnt == 0) return "IDENTICAL";
    if (cnt == 1) return "CLOSE";
    return "DIFFERENT";
}

int main() {
    string s, t;
    while (cin >> s, s != ".") {
        cin >> t;
        cout << solve(s, t) << endl;
    }
    return 0;
}

C++: #include<stdio.h>

int main()
{
	char s1[100][201],s2[100][201],a1[201],a2[201];
	int c,count,i,t,str,count_s1,count_s2;
	int br=0,judge=0,j,k;
	
	while(1)
	{
		j=0;
		k=0;
		count=0;
		count_s1=0;
		count_s2=0;
		
		while((c=getchar())!='\n')
		{
			if(c=='.')
			{
				br=1;
				break;
			}
			if(c=='"')
			{
				judge=1-judge;
				if(judge)
				{
					count_s1++;
					str=0;
				}
				else s1[count_s1-1][str]='\0';
			}
			if(judge)
			{
				s1[count_s1-1][str]=c;
				str++;
			}
			else
			{
				a1[j]=c;
				j++;
			}
		}
		a1[j]='\0';
		if(br) break;
		
		while((c=getchar())!='\n')
		{
			if(c=='"')
			{
				judge=1-judge;
				if(judge)
				{
					count_s2++;
					str=0;
				}
				else s2[count_s2-1][str]='\0';
			}
			if(judge)
			{
				s2[count_s2-1][str]=c;
				str++;
			}
			else
			{
				a2[k]=c;
				k++;
			}
		}
		a2[k]='\0';
		for(int i=0;;i++)
		{
			if(a1[i]=='\0' && a2[i]=='\0') break;
			if(a1[i]!=a2[i])
			{
				count=2;
				break;
			}
		}
		if(count_s1==count_s2 && count==0)
		{
			for(int i=0;i<count_s1;i++)
			{
				//printf("%s\n",s1[i]);
				//printf("%s\n\n",s2[i]);
				for(int t=0;;t++)
				{
					if(s1[i][t]=='\0'&&s2[i][t]=='\0') break;
					if(s1[i][t]!=s2[i][t])
					{
						count++;
						break;
					}
					
				}
			}
		}
		else count=2;
		if(count==0) printf("IDENTICAL\n");
		else if(count==1) printf("CLOSE\n");
		else printf("DIFFERENT\n");
	}
	return 0;
}