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>
#include <vector>
using namespace std;

int main(){

  while(true){
    int wrongTime = 0;
    string str_in;
    string str_ans;
    vector <string> sub_in;
    vector <string> sub_ans;
    //input--------------------
    cin >> str_in;
    if( str_in == ".") break;
    cin>> str_ans;
    //split---------------------
    int start = 0;
    for(int i=0; i < str_in.size() ; i++){
      if(str_in[i] == '\"') {
        sub_in.push_back(str_in.substr(start,i-start));
        start = i+1;
      }
    }
    sub_in.push_back(str_in.substr(start,str_in.size()-start));
    start = 0;
    for(int i=0; i < str_ans.size() ; i++){
      if(str_ans[i] == '\"') {
        sub_ans.push_back(str_ans.substr(start,i-start));
        start = i+1;
      }
    }
    sub_ans.push_back(str_ans.substr(start,str_ans.size()-start));
    //split check
      // for(int i = 0; i < sub_in.size(); i++) cout << sub_in[i] << endl;
      // for(int i = 0; i < sub_ans.size(); i++) cout << sub_ans[i] << endl;

    //conpare
    if(sub_in.size() != sub_ans.size()){
      wrongTime = 2;
    }else{
      wrongTime = 0;
      for(int i = 0; i < sub_in.size(); i++){
        if(i%2 == 1){
          if(sub_in[i] != sub_ans[i]) wrongTime ++;
        }else{
          if(sub_in[i] != sub_ans[i]) wrongTime += 2;
        }
      }
    }
    if(wrongTime == 0) cout << "IDENTICAL" << endl;
    else if(wrongTime <= 1) cout << "CLOSE" << endl;
    else cout << "DIFFERENT" << endl;
    sub_in.clear();
    sub_ans.clear();
  }

  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;
}

C++: #include <bits/stdc++.h>
#define chmin(a, b) ((a)=min((a), (b)))
#define chmax(a, b) ((a)=max((a), (b)))
#define fs first
#define sc second
#define eb emplace_back
using namespace std;
 
typedef long long ll;
typedef pair<int, int> P;
typedef tuple<int, int, int> T;
 
const ll MOD=1e9+7;
const ll INF=1e18;
 
int dx[]={1, -1, 0, 0};
int dy[]={0, 0, 1, -1};


int main(){
    char a[210],b[210];
    while(1){
        cin >> a;
        if(a[0] == '.')break;
        cin >> b;
        int dif = 0,ai = 0,bi = 0;
        for(;ai < strlen(a) || bi < strlen(b);ai++,bi++){
            if(a[ai] == '"' && b[bi] == '"'){
                for(int i = 1;ai + i < strlen(a);i++){
                    if(a[ai+i] == '"' && b[bi+i] == '"'){
                        ai += i; bi += i;
                        break;
                    }else if(a[ai+i] != b[bi+i]){
                        dif++;
                        if(dif >= 2) break;
                        int add = 0;
                        for(add = 0;a[ai+i+add] != '"';add++) ;
                        ai = ai + i + add;
                        for(add = 0;b[bi+i+add] != '"';add++) ;
                        bi = bi + i + add;
                        break;
                    }
                }
                if(dif >= 2)break;
            }else if(a[ai] != b[bi]){
                dif = 3;
                break;
            }
        }
        if(ai == strlen(a) && bi == strlen(b) && dif == 0){
            cout << "IDENTICAL" << endl;
        }else if(dif == 1){
            cout << "CLOSE" << endl;
        }else{
            cout << "DIFFERENT" << endl;
        }
    }
}

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

int main(){
  string str1,str2;

  while(cin >> str1, str1!="."){
    cin >> str2;
    bool frg = true;
    int er_cnt = 0;
    int j=0;
    int v1_cnt = 0;
    int v2_cnt = 0;
    for(int i=0; i<str1.size(); ++i){
      vector<char> v1;
      vector<char> v2;

      while(str1[i]!= '"' && i<str1.size()){
	v1.push_back(str1[i]);
	++i;
      }
      if(str1[i+1]=='"'){++v1_cnt;}
      
      while(str2[j]!='"' && j<str2.size()){
	v2.push_back(str2[j]);
	++j;
      }
      if(str2[j+1]=='"'){++v2_cnt;}
      ++j;
      
      if(v1!=v2 || v1.size()!=v2.size()){
	if(frg == true){
	  er_cnt = er_cnt+2;
	}else if(frg == false){
	  ++er_cnt;
	}
      }
      if(v1_cnt!=v2_cnt){er_cnt += 2;}

      frg = !frg;
    }

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