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<sstream>
#include<string>

int check(std::string s1,std::string s2){
  int n1=0;
  int n2=0;
  int c1=n1+1;
  int c2=n2+1;
  int count;
  bool diff=false;
  while(1){
    if(s1[c1] =='"' and  s2[c2]=='"') {
      n1=c1;
      n2=c2;
      break;
    }
    if(s1[c1]!=s2[c2]&&!diff) {
      count++;
      diff = true;
    }
    if(s1[c1]!='"')c1++;
    if(s2[c2]!='"') c2++;
  }
  return count;
}


int main(){
  std::string str1,str2;
  int l1,l2,mistakes,j=0;
  int ok[1000]={0};
  while(str1[0]!='.'){
    mistakes=0;
    std::getline(std::cin,str1);
    l1=str1.size();
    if(str1[0]=='.') break;
    std::getline(std::cin,str2);
    l2=str2.size();

    for(int i=0;i<l1;i++){
      if(str1[i]=='"' and str2[i]=='"'){
	mistakes=check(str1,str2);
	break;
      }else if(str1[i]!=str2[i]){
	mistakes++;
      }
    }
    if(mistakes==0 and l1==l2){
      ok[j]=0;
    }else if(mistakes==1){
      ok[j]=1;
    }else{
      ok[j]=2;
    }
    j++;
  }

  for(int i=0;i<j;i++){
    if(ok[i]==0){
      std::cout<<"IDENTICAL\n";
    }else if(ok[i]==1){
      std::cout<<"CLOSE\n";
    }else{
      std::cout<<"DIFFERENT\n";
    }
  }
}

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 = "DEFFRENT";
		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;
}

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

using namespace std;

string s, s2;
string t, t2;
vector<string> vec, vec2;

string calc(string s, vector<string> &vec)
{
  string t, u; bool flag = false;
  vec.clear();
  for(int i = 0; i < s.size(); i++){
    if(flag){
      if(s[i] == '\"'){
        flag = false;
        vec.push_back(u);
      }
      else u += s[i];
    }
    else{
      if(s[i] == '\"'){
        flag = true;
        t += s[i];
        u = "";
      }
      else{
        t += s[i];
      }
    }
  }
  return t;
}

int main(void)
{
  while(1){
    cin >> s >> s2;
    if(s == ".") break;

    t = calc(s, vec);
    t2 = calc(s2, vec2);

    /*cout << t << endl;
    cout << t2 << endl;
    cout << endl;*/

    if(vec.size() != vec2.size() || t != t2){
      cout << "DIFFERENT" << endl;
      continue;
    }
    int cnt = 0;
    for(int i = 0; i < vec.size(); i++){
      if(vec[i] != vec2[i]) cnt++;
    }
    if(cnt == 0) cout << "IDENTICAL" << endl;
    else if(cnt == 1) cout << "CLOSE" << endl;
    else cout << "DIFFERENT" << endl;
  }
  return 0;
}

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

using namespace std;


int main(){
	while(1){
		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 (1) {
			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<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;
}