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);
	  //cout<<"str:"<<str<<endl;
	  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);
	  //cout<<"str:"<<str<<endl;
	  n2s.push_back(str);
	  start=-1;
	}
      }
    }
    if(start==-1){
      //cout<<"-1"<<end;
      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;
    }
    /*
    for(int i=0;i<n1ns.size();i++){
      cout<<n1ns[i]<<" ";
    }
    cout<<endl;
    
    for(int i=0;i<n2ns.size();i++){
      cout<<n2ns[i]<<" ";
    }
    cout<<endl;
    */
    
    if(count==1){
      cout<<"CLOSE"<<endl;
    }else if(count==0){
      cout<<"IDENTICIAL"<<endl;
    } else{
      cout<<"DIFFERENT"<<endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#define LENGTH 201
using namespace std;
char str1[LENGTH];
char str2[LENGTH];

int main(){
    while(true){
        int cnt = 0;
        cin >> str1;
        if(str1[0] == '.')
            break;
        cin >> str2;
        for(int i = 0;i < LENGTH;i++){
            if(str1[i] != str2[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>
#include <vector>
using namespace std;

int main(){

  while(true){
    int wrongTime = 0;
    string str_in;
    string str_ans;
    vector <string> sub_in;
    vector <string> sub_ans;
    //input--------------------
    cin >> str_in;
    if( str_in == ".") break;
    cin>> str_ans;
    //split---------------------
    int start = 0;
    for(int i=0; i < str_in.size() ; i++){
      if(str_in[i] == '\"') {
        sub_in.push_back(str_in.substr(start,i-start));
        start = i+1;
      }
    }
    start = 0;
    for(int i=0; i < str_ans.size() ; i++){
      if(str_ans[i] == '\"') {
        sub_ans.push_back(str_ans.substr(start,i-start));
        start = i+1;
      }
    }

    if(sub_in.size() == 0) sub_in.push_back(str_in);
    if(sub_ans.size() == 0) sub_ans.push_back(str_ans);
    //split check
      // for(int i = 0; i < sub_in.size(); i++) cout << sub_in[i] << endl;
      // for(int i = 0; i < sub_ans.size(); i++) cout << sub_ans[i] << endl;
    //conpare
    if(sub_in.size() != sub_ans.size()){
      wrongTime = 2;
    }else{
      wrongTime = 0;
      for(int i = 0; i < sub_in.size(); i++){
        if(i%2 == 1){
          if(sub_in[i] != sub_ans[i]) wrongTime ++;
        }else{
          if(sub_in[i] != sub_ans[i]) wrongTime += 2;
        }
      }
    }
    if(wrongTime == 0) cout << "IDENTICAL" << endl;
    else if(wrongTime <= 1) cout << "CLOSE" << endl;
    else cout << "DIFFERENT" << endl;
    sub_in.clear();
    sub_ans.clear();
  }

  return 0;
}

C++: #include <bits/stdc++.h>
#define int long long
#define INF 1e+18
using namespace std;

vector<string> constant[2],other[2];

void rekkyo(string &s,vector<string> &vec1,vector<string> &vec2){
	int op = 0;
	string tmp = "";
	for(int i = 0;i < s.length();i++){
		if(s[i] == '\"'){
			(op ? vec1 : vec2).push_back(tmp);
			tmp = "";
			op = !op;
		}else tmp += s[i];
	}
	if(tmp != "") (op ? vec1 : vec2).push_back(tmp);
}

signed main(){
	string s1,s2;
	while(cin >> s1,s1 != "."){
		cin >> s2;
		for(int i = 0;i < 2;i++){
			constant[i].clear();
			other[i].clear();
		}
		rekkyo(s1,constant[0],other[0]);
		rekkyo(s2,constant[1],other[1]);
		int difc = 0,difo = 0;
		if(constant[0].size() != constant[1].size()) difc = 10;
		else{
			for(int i = 0;i < constant[0].size();i++){
				if(constant[0][i] != constant[1][i]) difc++;
			}
		}
		if(other[0].size() != other[1].size()) difo = 10;
		else{
			for(int i = 0;i < other[0].size();i++){
				if(other[0][i] != other[1][i]) difo++;
			}
		}
		if(!difo && !difc) cout << "IDENTICAL" << endl;
		else if(!difo && difc == 1) cout << "CLOSE" << endl;
		else cout << "DIFFERENT" << endl;
	}
}