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<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 f1=s1;
	string f2=s2;
	
	while(true){
		size_t d1b =t1.find('\"');
		if(d1b==string::nops)
			break;
		
		t1.replace(d1b,1,"@");
		
		size_t d1e=t1.find('\"');
		t1.replace(d1e,1,"@");		

		size_t d2b =t2.find('\"');
		if(d2b==string::nops)
			break;
		t2.replace(d2b,1,"@");
		
		size_t d2e=t2.find('\"');
		t2.replace(d2e,1,"@");

		string u1=s1;
		u1.replace(d1b+1,d1e-d1b-1,"");
		string u2=s2;
		u2.replace(d2b+1,d2e-d2b-1,"");
		
		if(u1==u2){
			t1=u1;
			t2=u2;
			break;
		}
	}
	if(t1==t2){
		cout<<"CLOSE"<<endl;
	}else{
		cout<<"DIFFERENT"<<endl;
	}
	}
return 0;
}

C++: #include <cmath>
#include <iostream>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <utility>
#include <iomanip>

#define int long long int
#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;

typedef pair<int, int> P;

const int INF = 1e15;
const int MOD = 1e9+7;

signed main(){
    string s;
    cin >> s;
    while(s != "."){
        string t;
        cin >> t;

        if(s == t){
            cout << "INDENTICAL" << endl;
            cin >> s;
            continue;
        }

        vector<string> xs;
        vector<string> xt;
        int i = 0;
        while(i < (int)s.length()){
            string tmp;
            if(s[i] == '\"'){
                i++;
                tmp = "";
                while(s[i] != '\"'){
                    tmp.push_back(s[i]);
                    i++;
                }
                i++;
                xs.push_back(tmp);
                continue;
            }

            tmp = "";
            while(s[i] != '\"' && i < (int)s.length()){
                tmp.push_back(s[i++]);
            }
            xt.push_back(tmp);
        }

        vector<string> ys;
        vector<string> yt;
        i = 0;
        while(i < (int)t.length()){
            string tmp;
            if(t[i] == '\"'){
                i++;
                tmp = "";
                while(t[i] != '\"'){
                    tmp.push_back(t[i]);
                    i++;
                }
                i++;
                ys.push_back(tmp);
                continue;
            }

            tmp = "";
            while(t[i] != '\"' && i < (int)t.length()){
                tmp.push_back(t[i++]);
            }
            yt.push_back(tmp);
        }

        if(xs.size() != ys.size() || xt.size() != yt.size()){
            cout << "DIFFERENT" << endl;
            cin >> s;
            continue;
        }

        int c = 0;
        rep(i, (int)xs.size()){
            if(xs[i] != ys[i]){
                c++;
            }
        }

        int d = 0;
        rep(i, (int)xt.size()){
            if(xt[i] != yt[i]){
                d++;
            }
        }

        if(d == 0 && c == 1){
            cout << "CLOSE" << endl;
            cin >> s;
            continue;
        }
        cout << "DIFFERENT" << endl;

        cin >> s;
    }

    return 0;
}