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;

using ll = long long;
using ld = long double;
using P = pair<int, int>;
constexpr ld EPS = 1e-12;
constexpr int INF = numeric_limits<int>::max() / 2;
constexpr int MOD = 1e9 + 7;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    string s1, s2;
    while (cin >> s1, s1 != ".")
    {
        cin >> s2;
        vector<string> v1, v2;
        string tmp = "";
        int cnt = 0;
        int len = s1.length();
        for (int i = 0; i < len; i++)
        {
            if (s1[i] == '"')
            {
                if (cnt == 0)
                {
                    v1.push_back(tmp);
                    tmp = "";
                    tmp += '"';
                    cnt++;
                }
                else
                {
                    tmp += '"';
                    v1.push_back(tmp);
                    tmp = "";
                    cnt = 0;
                }
                continue;
            }
            tmp += s1[i];
        }
        v1.push_back(tmp);

        tmp = "";
        cnt = 0;
        len = s2.length();
        for (int i = 0; i < len; i++)
        {
            if (s2[i] == '"')
            {
                if (cnt == 0)
                {
                    v2.push_back(tmp);
                    tmp = "";
                    tmp += '"';
                    cnt++;
                }
                else
                {
                    tmp += '"';
                    v2.push_back(tmp);
                    tmp = "";
                    cnt = 0;
                }
                continue;
            }
            tmp += s2[i];
        }
        v2.push_back(tmp);

        if (v1.size() != v2.size())
        {
            cout << "DIFFERENT" << endl;
            continue;
        }
        cnt = 0;
        int sz = v1.size();
        for (int i = 0; i < sz; i++)
        {
            if (v1[i] == v2[i])
                continue;
            if (v1[i][0] == '"' && v2[i][0] == '"')
            {
                cnt++;
            }
            else
            {
                cnt = 100;
            }
        }
        if (cnt == 0)
            cout << "IDENTICAL" << endl;
        else if (cnt == 1)
            cout << "CLOSE" << endl;
        else
            cout << "DIFFERENT" << endl;
    }
}

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

using i64 = int64_t;

int main(){
    string s1;
    while(cin >> s1, s1 != "."){
        string s2;
        cin >> s2;
        if(s1 == s2){
            cout << "IDENTICAL" << endl;
            continue;
        }
        int n1 = 0, n2 = 0;
        for(auto c: s1){
            if(c == '"')n1++;
        }
        for(auto c: s2){
            if(c == '"')n2++;
        }
        if(n1 != n2){
            cout << "DIFFERENT" << endl;
            continue;
        }
        s1 += "\""; s2 += "\"";
        int s1left = 0, s2left = 0, cnt = 0;
        bool quote = false, ok = true;
        while(s1left < s1.size() && s2left < s2.size()){
            int s1right = s1left, s2right = s2left;
            while(s1right < s1.size() && s1[s1right] != '"')s1right++;
            while(s2right < s2.size() && s2[s2right] != '"')s2right++;
            string t1 = s1.substr(s1left, s1right-s1left), t2 = s2.substr(s2left, s2right-s2left);
            //cerr << t1 << " " << t2 << endl;
            if(quote){
                if(t1 != t2)cnt++;
            }else{
                if(t1 != t2){
                    ok = false;
                    break;
                }
            }
            s1left = s1right+1;
            s2left = s2right+1;
            quote ^= 1;
        }
        //cerr << ok << " " << cnt << endl;
        if(!ok || cnt > 1){
            cout << "DIFFERENT" << endl;
        }else{
            cout << "CLOSE" << endl;
        }
    }

    return 0;
}

C++: #include <bits/stdc++.h>

#define ALL(a) (a).begin(), (a).end()
#define llong long long

using namespace std;

string pickword(const string &str, int &i){
	int j = 0;
	for(; i+j < str.size() && str[i+j] != '"'; j++);
	string ret = j == 0 ? "" : str.substr(i, j);
	i += j;
	if(i+j == str.size()){
		i += j;
		return to_string(i+j) + str;
	}
	return ret;
}

signed main(){
	while(true){
		string str; cin >> str;
		if(str == ".")break;
		string tgt; cin >> tgt;
		bool yellow = false;
		int ans = 1;
		for(int i = 0, j = 0; i < str.size() && j < str.size(); i++, j++){
			if(str[i] == tgt[j] && str[i] == '"'){
				i++; j++;
				string word = pickword(str, i);
				if(word != pickword(tgt, j)){
					if(yellow){
						ans = -1;
						break;
					}
					else{
						yellow = true;
						ans = 0;
					}
				}
			}
			if(str[i] != tgt[j]){
				ans = -1;
				break;
			}
		}
		if(ans == 1)cout << "IDENTICAL" << endl;
		else if(ans == 0)cout << "CLOSE" << endl;
		else cout << "DIFFERENT" << endl;
	}

	return 0;
}