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>
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep2(i, a, b) for(int i = (a); i <= (b); ++i)
#define ll long long

main() {
    while(1) {
        string s;
        cin >> s;
        string t;
        cin >> t;
        if(cin.eof()) break;
        auto f = [](string s) {
            string res;
            vector<string> a;
            rep(i, s.size()) {
                if(s[i] == '\"') {
                    i++;
                    a.emplace_back(string());
                    while(s[i] != '\"') { a.back().push_back(s[i++]); }
                    res.push_back('"');
                } else
                    res.push_back(s[i]);
            }
            return make_pair(res, a);
        };
        vector<string> ss, tt;
        string S, T;
        tie(S, ss) = f(s);
        tie(T, tt) = f(t);
        if(S == T and ss == tt) {
            cout << "IDENTICAL\n";
            continue;
        }
        bool flag = true;
        if(S == T) {
            int cnt = 0;
            if(ss.size() != tt.size())
                flag = false;
            else {
                rep(i, ss.size()) cnt += ss[i] != tt[i];
                flag = cnt < 2;
            }
        } else
            flag = false;
        cout << (flag ? "CLOSE\n" : "DIFFERENT\n");
    }
}

C++: print"hello";print123
print"hello";print123
read"B1input";solve;output;
read"B2";solve;output;
read"C1";solve;output"C1ans";
read"C2";solve;output"C2ans";
""""""""
"""42"""""
slow"program"
fast"code"
"super"fast"program"
"super"faster"program"
X""
X
I"S""CREAM"
I"CE""CREAM"
11"22"11
1"33"111
.

C++: #include <iostream>
#include <string>
#include <sstream>

int main(){
    int cnt;
    bool odd;
    bool flag = false;
    std::string str1;
    std::string str2;
    std::string tmp1;
    std::string tmp2;
    std::string tmp3;
    while(true){
        odd = false;
        std::cin >> str1;
        std::cin >> str2;
        cnt = 0;
        std::istringstream iss1(str1);
        std::istringstream iss2(str2);
        while(std::getline(iss1,tmp1,'"')){
            if(std::getline(iss2,tmp3,'"')){
                std::istringstream iss3(tmp3);
                iss3 >> tmp2;
                std::cout << tmp2 << "\n"; 
                if(tmp2 == "."){
                    flag = true;
                    break;
                }
                if(tmp1!=tmp2){
                    if(odd){
                        cnt++;
                    }else{
                        cnt += 2;
                        break;
                    }
                }
            }else{
                cnt+=2;
                break;
            }
            
            if(odd){
                odd = false;
            }else{
                odd = true;
            }
        }
        if(flag){
            break;
        }
        if(cnt==0){
            std::cout << "IDENTICAL\n";
        }else if(cnt==1){
            std::cout << "CLOSE\n";
        }else{
            std::cout << "DIFFERENT\n";
        }
    }
}

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

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

vector<string> split(string s, const string &b){
  vector<string> res;
  while(1){
    int pos = s.find(b);
    if(pos == -1) break;
    res.push_back(s.substr(0,pos));
    s = s.substr(pos+1,s.size());
  }
  if(s != "") res.push_back(s);
  return res;
}

int main(){
  string s, t;
  while(cin >> s, s != "."){
    cin >> t;
    vector<string> as = split(s,"\""), bs = split(t,"\"");
    if(as.size() != bs.size()){
      cout << "DIFFERENT" << endl;
      continue;
    }
    int even = 0, odd = 0;
    rep(i, as.size()){
      if(i % 2 == 0) even += as[i] != bs[i];
      else odd += as[i] != bs[i];
    }
    if(even != 0 or odd > 1) cout << "DIFFERENT" << endl;
    else if(odd == 1) cout << "CLOSE" << endl;
    else cout << "IDENTICAL" << endl;
  }
}