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<algorithm>
#include<vector>

using namespace std;
int main()
{
  while(1){
    int count;
    string n1;
    string n2;
    vector<string> n1s(0);
    vector<string> n2s(0);
    vector<string> n1ns(0);
    vector<string> n2ns(0);
    cin>>n1;
    if(n1==".") return 0;
    cin>>n2;
    int l1=n1.size();
    int l2=n2.size();
   
    int start=-1;
    int end=-2;
    for(int i=0;i<l1;i++){
      if(n1[i]=='"'){
	if(start==-1){
	  start=i+1;
	  string str=n1.substr(end+2,start-end-3);
	  n1ns.push_back(str);
	}else{
	  end=i-1;
	  string str=n1.substr(start,end-start+1);
	  n1s.push_back(str);
	  start=-1;
	}
      }
    }
    if(start==-1){
      string str=n1.substr(end+2,l1-(end+2));
      n1ns.push_back(str);
    }
    start=-1;
    end=-2;
    for(int i=0;i<l2;i++){
      if(n2[i]=='"'){
	if(start==-1){
	  start=i+1;
	  string str=n2.substr(end+2,start-end-3);
	  n2ns.push_back(str);
	}else{
	  end=i-1;
	  string str=n2.substr(start,end-start+1);
	  n2s.push_back(str);
	  start=-1;
	}
      }
    }
    if(start==-1){
      string str=n2.substr(end+2,l2-(end+2));
      n2ns.push_back(str);
    }
    int s1=n1s.size();
    int s2=n2s.size();
    int ma=s1-s2;
    if(ma==0){
      count=0;
      for(int i=0;i<s1;i++){
	if(n2s[i]!=n1s[i]) count++;
      }      
    }else{
      count=-1;
    }
    for(int i=0;i<n1ns.size();i++){
      if(n1ns[i]!=n2ns[i]) count=-1;
    }
    if(count==1){
      cout<<"CLOSE"<<endl;
    }else if(count==0){
      cout<<"IDENTICIAL"<<endl;
    } else{
      cout<<"DIFFERENT"<<endl;
    }
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define PB push_back

void f(string s,string t){
  vector<string> sv,sw,tv,tw;

  int j=0;
  string u;
  for(int i=0;i<s.size();i++){

    if(s[i]=='\"'){
      if(j%2){
        sw.PB(u);
      }
      else{
        sv.PB(u);
      }
      u="";
      j++;
    }
    else{
      u+=s[i];
    }
  }
  if(j%2){
    sw.PB(u);
  }
  else{
    sv.PB(u);
  }
  u="";
  j++;


  j=0;
  
  for(int i=0;i<t.size();i++){
    if(t[i]=='\"'){
      if(j%2){
        tw.PB(u);
      }
      else{
        tv.PB(u);
      }
      u={};
      j++;
    }
    else{
      u+=t[i];
    }
  }
  
  if(j%2){
    tw.PB(u);
  }
  else{
    tv.PB(u);
  }
  u="";
  j++;


  if(sv.size()!=tv.size()||sw.size()!=tw.size()){
    cout<<"DIFFERENT"<<endl;
    return;
  }

  for(int i=0;i<sv.size();i++){
    if(sv[i]!=tv[i]){
      cout<<"DIFFERENT"<<endl;
      return;
    }
  }

  int d=0;
  for(int i=0;i<sw.size();i++){
    if(sw[i]!=tw[i]){
      d++;
    }
  }

  if(d>1){
    cout<<"DIFFERENT"<<endl;
    return;
  }
  if(d==1){
    cout<<"CLOSE"<<endl;
    return;
  }

  cout<<"IDENTICAL"<<endl;
}




int main(){
  string s,t;
  while(true){
    cin>>s;
    if(s==".") break;
    cin>>t;
    f(s,t);
  }

}

C++: #define _USE_MATH_DEFINES

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>

using namespace std;

int main(){
	
	while(true){
		string str1, str2;
		cin >> str1;
		if(str1[0] == '.' && str1.size() == 1){
			break;
		}
		cin >> str2;
		vector<string> v1, v2;
		string s = "";
		for(int i = 0; i < str1.size(); i++){
			if(str1[i] == '"'){
				v1.push_back(s);
				s = "";
			}else{
				string ss = " ";
				ss[0] = str1[i];
				s = s + ss;
			}
		}
		v1.push_back(s);
		s = "";
		for(int i = 0; i < str2.size(); i++){
			if(str2[i] == '"'){
				v2.push_back(s);
				s = "";
			}else{
				string ss = " ";
				ss[0] = str2[i];
				s = s + ss;
			}
		}
		v2.push_back(s);
		if(v1.size() != v2.size()){
			cout << "DIFFERENT" << endl;
		}else{
			int cnt = 0;
			for(int i = 0; i < v1.size(); i++){
				//cout << v1[i] << " " << v2[i] << endl;
				if(v1[i] != v2[i]){
					if(i % 2 == 0){
						cnt += 2;
					}else{
						cnt++;
					}
				}
			}
			if(cnt == 0){
				cout << "IDENTICAL" << endl;
			}else if(cnt == 1){
				cout << "CLOSE" << endl;
			}else{
				cout << "DIFFERENT" << endl;
			}
		}
	}
	
	return 0;
	
}

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

string s;
string tt;
int ans;
int ff,fff;

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