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 <iostream>
#include <string>
#define LENGTH 201
using namespace std;

int main(){
    while(true){
        string str1,str2;
        int cnt1c = 0,cnt2c = 0,cnt1s = 0,cnt2s = 0;
        cin >> str1;
        if(str1[0] == '.')
            break;
        cin >> str2;
        for(int i = 0;i < LENGTH;i++){
            if(str1[i] == '"')
                cnt1c++;
            if(str1[i] == ';')
                cnt1s++;
            if(str2[i] == '"')
                cnt2c++;
            if(str2[i] == ';')
                cnt2s++;
        }
        if(((cnt1c + cnt1s) - (cnt2c + cnt2s)) == 0){
            if(str1 == str2)
                cout << "IDENTICAL" << endl;
            else
                cout << "CLOSE" << endl;
        }
        else if(((cnt1c + cnt1s) - (cnt2c + cnt2s)) == 2)
            cout << "CLOSE" << endl;
        else
            cout << "DIFFERENT" << endl;
        
    }

    return 0;
}

C++: #include "bits/stdc++.h"

#define REP(i,n) for(ll i=0;i<ll(n);++i)
#define RREP(i,n) for(ll i=ll(n)-1;i>=0;--i)
#define FOR(i,m,n) for(ll i=m;i<ll(n);++i)
#define RFOR(i,m,n) for(ll i=ll(n)-1;i>=ll(m);--i)
#define ALL(v) (v).begin(),(v).end()
#define UNIQUE(v) v.erase(unique(ALL(v)),v.end());
#define INF 1000000001ll
#define MOD 1000000007ll
#define EPS 1e-9

const int dx[8] = { 1,1,0,-1,-1,-1,0,1 };
const int dy[8] = { 0,1,1,1,0,-1,-1,-1 };


using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;



int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	vector<string> s(2);
	while (cin >> s[0]) {
		if (s[0] == ".")break;
		cin >> s[1];
		vector<vector<string>> a(2), b(2);
		REP(k, 2) {
			bool f = false;
			string tmp;
			REP(i, s[k].size()) {
				if (s[k][i] == '\"') {
					if (f) {
						b[k].push_back(tmp);
						tmp = "";
					}
					else {
						a[k].push_back(tmp);
						tmp = "";
					}
					f = !f;
				}
				else {
					tmp += s[k][i];
				}
			}
			if (tmp != "")a[k].push_back(tmp);
		}
		if (a[0] != a[1]) {
			cout << "DIFFERENT" << endl;
		}
		else {
			
			if (b[0].size() != b[1].size()) {
				cout << "DIFFERENT" << endl;
			}
			else {
				int cnt = 0;
				REP(i, b[0].size()) {
					if (b[0][i] != b[1][i])cnt++;
				}
				if (cnt == 0)cout << "IDENTICAL" << endl;
				else if (cnt == 1)cout << "CLOSE" << endl;
				else cout << "DIFFERENT" << endl;
			}
		}
	}
}