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 <stdio.h>
#include <iostream>
#include <vector>
#include <string>
using namespace std;

string s;
string tt;
int ans;
int ff;

int main(){
  cin >> s;
  while(s!="."){
    ans=0;
    ff=0;
    int i=0;
    int j=0;
    cin >> tt;
    for(;i<int(s.size())&&j<int(tt.size());){
      if(s[i]==tt[j]&&s[i]!=0x22&&tt[j]!=0x22){
        ++i;
        ++j;
        continue;
      }
      if(s[i]!=tt[j]){
        ans=1;
        break;
      }
      if(s[i]==0x22&&tt[j]==0x22){
        ++i;
        ++j;
        if(s[i]!=tt[j]){
          ++ff;
        }
        for(;s[i]!=0x22&&tt[j]!=0x22;){
          if(s[i]!=tt[j]){
            ++ff;
            break;
          }
          ++i;
          ++j;
        }
        while(s[i]!=0x22){
          ++i;
        }
        while(tt[j]!=0x22){
          ++j;
        }
        ++i;
        ++j;
      }

      if(ans==1)break;
    }
    if(i==int(s.size())&&j==int(tt.size())){}
    else{
      ans=1;
    }
    if(ans==1||ff>=2){
      printf("DIFFERENT\n");
    }
    else if(ff==0){
      printf("IDENTICAL\n");
    }
    else{
      printf("CLOSE\n");
    }
    cin >> s;
  }
}

C++: //include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <climits>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <queue>
#include <random>
#include <cctype>
#include <complex>
#include <regex>

using namespace std;

#define C_MAX(a, b) ((a)>(b)?(a):(b))
#define SHOW_VECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOW_MAP(v) {std::cerr << #v << endl; for(const auto& xxx: v){std::cerr << xxx.first << " " << xxx.second << "\n";}}

vector<string> getColon(string str) {
    vector<string> ret;

    string s = "a";
    bool read = false;

    for (int i = 0; i < str.size(); i++) {
        if (read) {
            if (str[i] == '"') {
                ret.push_back(s);
                s = "a";
                read = false;
            } else {
                s += str[i];
            }
        } else {
            if (str[i] == '"') read = true;
        }
    }
    return ret;
}

vector<string> getNotColon(string str) {
    vector<string> res;
    string s = "";
    bool read = true;
    for (int i = 0; i < str.size(); i++) {
        if (read) {
            if (str[i] == '"') {
                if (!s.empty())
                    res.push_back(s);
                s = "";
                read = false;
            } else {
                s += str[i];
            }
        } else {
            if (str[i] == '"') read = true;
        }
    }
    if (!s.empty()) res.push_back(s);
    return res;
}

int main() {

    while (true) {

        string s1, s2;
        cin >> s1;

        if (s1.size() == 1 && s1[0] == '.') break;
        cin >> s2;

        auto colon1 = getColon(s1);
        auto colon2 = getColon(s2);
        auto notColon1 = getNotColon(s1);
        auto notColon2 = getNotColon(s2);
        

        {
            if (notColon1.size() != notColon2.size()) {
                cout << "DIFFERENT" << endl;
                continue;
            }
            bool good = true;
            for (int i = 0; i < notColon1.size(); i++) if (notColon1[i] != notColon2[i]) good = false;
            if (!good) {
                cout << "DIFFERENT"<< endl;
                continue;
            }
        }

        {
            int count = 0;
            if (max(colon1.size(), colon2.size()) - min(colon1.size(), colon2.size()) >= 1) {
                cout << "DIFFERENT"<< endl;
                continue;
            }
            for (int i = 0; i < colon1.size(); i++) {
                if (colon1[i] != colon2[i]) count++;
            }
            if (count > 1) {
                cout << "DIFFERENT"<< endl;
                continue;
            }
            if (count == 1) {
                cout << "CLOSE"<< endl;
                continue;
            }
        }

        cout << "IDENTICAL"<< endl;
    }


    return 0;
}

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

using namespace std;

int main(){

  char s1[200]={0};
  char s2[200]={0};
  char t1[200]={0};
  char t2[200]={0};
char u1[200]={0};
  char u2[200]={0};

  int c=0,flag=0,j=0,k=0,l=0;

  cin>>s1>>s2;
 
  for(int i=0;i<200;i++){
    if(s1[i]=='"'){
      if(flag==0){
	flag=1;
	
      }else if(flag==1){
	flag=0;
	
      }
    }

    if(flag==1){
      t1[j]=s1[i];
      j++;    
    }

    if(flag==0){
      u1[l]=s1[i];
      l++;    
    }


  }
  j=0;
  l=0;
 for(int i=0;i<200;i++){

    if(s2[i]=='"'){
      if(flag==0){
	flag=1;
	
      }else if(flag==1){
	flag=0;
	
      }
    }

    if(flag==1){
      t2[j]=s2[i];
      j++;
    }

 if(flag==0){
      u2[l]=s2[i];
      l++;
    }

  }
 j=0;
 flag=0;


   
  for(int i=0;i<150;i++){


    if(flag==1){
    if(t1[j]!=t2[k]){
      c++;
      flag=0;
    }

    if(t1[j]=='"' && t2[k]!='"'){
      j--;
    }
    if(t2[k]=='"' && t1[j]!='"'){
      k--;
    }

    j++;
    k++;

    }

   if(t1[j]=='"' && t2[k]=='"'){
     flag=1;

    }


  }

  for(int i=0;i<200;i++){
    if(u1[i]!=u2[i]){
      c=2;
    }
  }

    if(c==0){
      cout<<"IDENTICAL"<<endl;
    }else if(c==1){
      cout<<"CLOSE"<<endl;
    }else{
      cout<<"DIFFERENT"<<endl;
    }
  
return 0;
}