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>

using namespace std;

int main(){

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

  int c=0,flag=0,j=0,k=0,l=0;
  for(int x=0;x<100;x++){
  cin>>s1;
  if(s1[0]=='.') break;
  cin>>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;

 /* cout<<t1<<endl;
 cout<<t2<<endl;
 cout<<u1<<endl;
 cout<<u2<<endl;*/

 //kyuukei~~~

   
  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;
}

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

using namespace std;

int main(){

  string s1,s2;
  bool t = false;

  while(1){
	int cnt = 0;
	cin>>s1;

	if(s1==".")
	  break;

	cin>>s2;

	if(s1==s2){
	  cout<<"IDENTICAL"<<endl;
	  continue;
	}

	else{
	  int i=0;
	  int j=0;
	  t = false;
	  
	  while(1){
		cout<<i<<" "<<j<<endl;

		if(s1[i]=='\0' &&  s2[j]=='\0')
		  break;
		
		if(s1[i]!=s2[j]){
		  cout<<"DIFFERENT"<<endl;
		  t = true;
		  break;
		}
		
		if(s1[i]=='\"' && s2[j]=='\"'){
		  i++;
		  j++;
		  
		  while(1){
			cout<<3<<endl;
			if(s1[i]=='\"' && s2[j]=='\"')
			  break;
			
			if(s1[i]!=s2[j]){
			  cnt++;
			  while(s1[i]!='\"')
				i++;
			  while(s2[j]!='\"')
				j++;
			  break;
			}
			i++;
			j++;
		  } 
		}
		  i++;
		  j++;
	  }
	  if(t == true)
		continue;
	}
	if(cnt == 1)
	  cout<<"CLOSE"<<endl;
	else
	  cout<<"DEFFERENT"<<endl;
  }
}

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

using namespace std;

int main() {
	while (1) {
		string s, t, ans;
		vector<string> sl, tl;
		cin >> s;
		if (s == ".")break;
		cin >> t;
		if (s.size() < t.size()) {
			string a;
			a = s;
			s = t;
			t = a;
		}
		string a="";
		for (int i = 0; i < s.size(); i++) {
			if (s[i] != '"')a.push_back(s[i]);
			else {
				sl.push_back(a);
				a = "";
				i++;
				while (s[i] != '"') {
					a.push_back(s[i]);
					i++;
				}
				sl.push_back(a);
				a = "";
			}
		}
		if (a.size() > 0)sl.push_back(a);
		a = "";
		for (int i = 0; i < t.size(); i++) {
			if (t[i] != '"')a.push_back(t[i]);
			else {
				tl.push_back(a);
				a = "";
				i++;
				while (t[i] != '"') {
					a.push_back(t[i]);
					i++;
				}
				tl.push_back(a);
				a = "";
			}
		}
		if (a.size() > 0)tl.push_back(a);
		if (sl.size() != tl.size())ans = "DEFFERENT";
		else {
			int cnt = 0;
			for (int i = 0; i < sl.size(); i++) {
				if (i % 2 == 0 && sl[i] != tl[i]) {
					cnt = 2;
					break;
				}
				else if (i % 2 == 1 && sl[i] != tl[i]) {
					cnt++;
				}
			}
			if (cnt > 1)ans = "DEFFERENT";
			else if (cnt == 1) ans = "CLOSE";
			else ans = "IDENTICAL";
		}
		cout << ans << endl;
	}
	return 0;
}