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>
using  namespace std;

int main(){
    while(true){
        string s1;
        cin >> s1;
        if(s1==".") break;
        string s2;
        cin >> s2;
        if(s1==s2){
            cout << "IDENTICAL" << endl;
            continue;
        }
        string t1 = s1;
        string t2 = s2;
        while(true){
            size_t d1b = t1.find('\"');
            if(d1b==string::npos) break;
            t1.replace(d1b, 1, "@");

            size_t d1e = t1.find('\"');
            t1.replace(d1e, 1, "@");

            size_t d2b = t2.find('\"');
            if(d2b==string::npos) break;
            t2.replace(d2b, 1, "@");

            size_t d2e = t2.find('\"');
            t2.replace(d2e, 1, "@");

            string u1 = s1;
            u1.replace(d1b+1, d1e-d1b-1, "");
            string u2 = s2;
            u2.replace(d2b+1, d2e-d2b-1, "");

            if(u1==u2){
                t1 = u1;
                t2 = u2;
                break;
            }
        }
        if(t1==t2){
            cout << "CLOSE" << endl;
        }else{
            cout << "DIFFERENT" << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
int main(){
	int i,j,k,l,m,lim,flag1=0,flag2,flag3,flag4,count=0,x,scou1=0,scou2=0;
	std::string s1;
	std::string s2;
	std::vector<std::string> ans;
	char str1[200],str2[200];
	while(1){
		gets(str1);
		i=0;
		while(str1[i]!=NULL){
			s1.push_back(str1[i]);
			i++;
		}
//		std::cout<<s1<<"\n";
		if(s1=="."){
//			std::cout<<s1<<"\n";
			break;
		}
		gets(str2);
		k=0;
		while(str2[k]!=NULL){
			s2.push_back(str2[k]);
			k++;
		}
//		std::cout<<s2<<"\n";
//		std::cout<<i<<"\n";
		scou1=0;
		scou2=0;
		flag1=0;
		flag2=0;
		flag3=0;
		flag4=0;
		if(i<k){
			l=i;
			lim=k;
		}else{
			l=k;
			lim=i;
		}
		j=0;
		m=0;
		for(int z=0;z<l;z++){
			if(s1[j]=='"'){
				scou1++;
			}
			if(s2[m]=='"'){
				scou2++;
			}
			
			std::cout<<s1[j]<<" "<<s2[m]<<"\n";
			
			if(s1[j]!=s2[m]){
				if(flag4==1){
					flag2=1;
					break;
				}
				if(scou1%2==1&&scou2%2==1){
					flag2=2;
					flag3=1;
				}else if(scou1%2==1){
					while(s1[j]!='"'){
						j++;
					}
					scou1++;
					flag2=2;
					flag3=1;
				}else if(scou2%2==1){
					while(s2[m]!='"'){
						m++;
					}
					scou2++;
					flag2=2;
					flag3=1;
				}else{
					flag2=1;
					break;
				}
				
			}
			
			if(flag3==1&&scou1%2==0&&scou2%2==0){
					flag4=1;
					std::cout<<"tutgihanai\n";
				}
			
			j++;
			m++;
		}
		
		if(m<lim&&j<lim){
			flag2=1;
		}
		
//		std::cout<<m<<j<<lim<<"\n";
		
		if(flag2==0){
			ans.push_back("IDENTICAL");
		}else if(flag2==1){
			ans.push_back("DEFFERENT");
		}else{
			ans.push_back("CLOSE");
		}
		std::cout<<ans[count]<<"\n";
		
		count++;
		s1.erase(s1.begin(),s1.end());
		s2.erase(s2.begin(),s2.end());
	}
	
	for(int j=0;j<count;j++){
		std::cout<<ans[j]<<"\n";
	}
	
	return 0;
}

C++: #include <iostream>
using namespace std;
int main() {
  while(true) {
    string s1;
    cin>>s1;
    if(s1==".")
      break;
    string s2;
    cin>>s2;
    bool foundDiff=false;
    bool different=false;
    auto it1=s1.begin(),it2=s2.begin();
    for(;it1!=s1.end()&&it2!=s2.end();++it1,++it2){
      if(*it1!=*it2){
        different=true;
        break;
      } else if(*it1=='"'){
        ++it1; ++it2;
        string mojiretsu1, mojiretsu2;
        while(*it1!='"')mojiretsu1+=*it1,++it1;
        while(*it2!='"')mojiretsu2+=*it2,++it2;
        if (mojiretsu1!=mojiretsu2){
          if(foundDiff) {
            different=true;
            break;
          }
          foundDiff=true;
        }
      }
    }
    if (it1!=s1.end()||it2!=s2.end()||different)
      cout<<"DIFFERENT";
    else if(foundDiff)
      cout<<"CLOSE";
    else
      cout<<"IDENTICAL";
    cout<<endl;

  }
  return 0;
}

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;
    for(int i=0; i<str1.size(); ++i){
      vector<char> v1;
      vector<char> v2;
      //cout << "frg1" << endl;
      while(str1[i]!= '"' && i<str1.size()){
	v1.push_back(str1[i]);
	++i;
      }
      v1.push_back(str1[i+1]);
      while(str2[j]!='"' && j<str2.size()){
	v2.push_back(str2[j]);
	++j;
      }
      ++j;
      v1.push_back(str2[j]);
      //cout << "frg3" << endl;
      if(v1!=v2 || v1.size()!=v2.size()){
	if(frg == true){
	  er_cnt = er_cnt+2;
	}else if(frg == false){
	  ++er_cnt;
	}
	//cout << "error type is <" << frg << ">" << endl;
       }
      //cout << "total error : " << er_cnt << endl;
      //cout << "frg4" << endl;
      frg = !frg;
    }

    //cout << "frg5" << endl;
    if(er_cnt == 0){
      cout << "IDENTICAL" << endl;
    }else if(er_cnt == 1){
	cout << "CLOSE" << endl;
      }else{
      cout << "DIFFERENT" << endl;
    }
    
  }
  return 0;
}