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(1){
		string s1;	
		cin>>s1;

		if(s1==".")
			break;

		string s2;
  		cin>>s2;	
		
		if(s1==s2){
			cout<<"IDENTICAL"<<endl;
		}
		
		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('\"');
			t1.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++: // g++ -std=c++11 a.cpp
#include<iostream>
#include<vector>
#include<string>
#include<algorithm>	
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<random>
#include<cstring>
#include<queue>
#include<stack>
#include<bitset>
#include<cstdio>
#include<sstream>
#include<iomanip>
#include<assert.h>
#include<typeinfo>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)
using namespace std;
//kaewasuretyuui
typedef long long ll;
//#define int ll
typedef int Def;
//typedef ll Def;
typedef pair<Def,Def> pii;
typedef vector<Def> vi;
typedef vector<vi> vvi;
typedef vector<pii> vp;
typedef vector<vp> vvp;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef pair<Def,pii> pip;
typedef vector<pip>vip;
#define mt make_tuple
typedef tuple<int,int,int> tp;
typedef vector<tp> vt;
template<typename A,typename B>bool cmin(A &a,const B &b){return a>b?(a=b,true):false;}
template<typename A,typename B>bool cmax(A &a,const B &b){return a<b?(a=b,true):false;}
//template<class C>constexpr int size(const C &c){return (int)c.size();}
//template<class T,size_t N> constexpr int size(const T (&xs)[N])noexcept{return (int)N;}
const double PI=acos(-1);
const double EPS=1e-7;
Def inf = sizeof(Def) == sizeof(long long) ? 2e18 : 1e9+10;
int dx[]={0,1,0,-1};
int dy[]={1,0,-1,0};
int main(){
	string s,t;
	while(cin>>s>>t,s!="."){
		vs A,a,B,b;
		string r="";
		bool h=false;
		rep(i,s.size()){
			if(s[i]=='"'){
				if(h)A.pb(r);
				else a.pb(r);
				r="";
				h^=1;
			}else r+=s[i];
		}
		if(r!="")a.pb(r);
		r="";
		rep(i,t.size()){
			if(t[i]=='"'){
				if(h)B.pb(r);
				else b.pb(r);
				r="";
				h^=1;
			}else r+=t[i];
		}
		if(r!="")b.pb(r);
		h=true;
		if(A.size()!=B.size())h=false;
		int co=0;
		if(h)rep(i,A.size())if(A[i]!=B[i])co++;
		if(co>1)h=false;
		if(a.size()!=b.size())h=false;
		if(h)rep(i,a.size())if(a[i]!=b[i])h=false;
		if(s==t)cout<<"IDENTICAL"<<endl;
		else if(h)cout<<"CLOSE"<<endl;
		else cout<<"DIFFERENT"<<endl;;
	}
}

C++: #include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <utility>
#include <string>
#include <stack>
#include <regex>

#define REP(i, n) for (int i = 0; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
#define vi vector<int>
#define vvi vector<vector<int>>
#define vl vector<long long>
#define vvl vector<vector<long long>>

using namespace std;

typedef long long ll;

std::vector<std::string> split(std::string str, char del)
{
  int first = 0;
  int last = str.find_first_of(del);

  std::vector<std::string> result;

  while (first < str.size())
  {
    std::string subStr(str, first, last - first);

    result.push_back(subStr);

    first = last + 1;
    last = str.find_first_of(del, first);

    if (last == std::string::npos)
    {
      last = str.size();
    }
  }

  return result;
}

int main()
{
  string s1;
  string s2;
  while (true)
  {
    bool close = false;
    cin >> s1;
    if (s1 == ".")
    {
      break;
    }
    cin >> s2;
    if (s1 == s2)
    {
      cout << "IDENTICAL" << endl;
      continue;
    }

    int c1 = 0;
    int c2 = 0;

    REP(i, s1.size())
    {
      if (s1[i] == '"')
      {
        c1++;
      }
    }
    REP(i, s2.size())
    {
      if (s2[i] == '"')
      {
        c2++;
      }
    }
    if (c1 != c2)
    {
      cout << "DIFFERENT" << endl;
      continue;
    }

    vector<string> v1 = split(s1, '"');
    vector<string> v2 = split(s2, '"');
    if (v1.size() != v2.size())
    {
      cout << "DIFFERENT" << endl;
      continue;
    }

    REP(i, v1.size())
    {
      if (i % 2 == 0)
      {
        if (v1[i] != v2[i])
        {
          cout << "DIFFERENT" << endl;
          break;
        }
      }
      else
      {
        if (v1[i] != v2[i] && close)
        {
          cout << "DIFFERENT" << endl;
          close = false;
          break;
        }
        else if (v1[i] != v2[i] && !close)
        {
          close = true;
        }
      }
    }
    if (close)
    {
      cout << "CLOSE" << endl;
    }
  }
  return 0;
}