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>
using namespace std;

int main(){
	while(1){
		string s1,s2;
		cin >> s1;
		if(s1 == ".") return 0;
		cin >> s2;
		string s11[201], s22[201];
		for(int i=0;i<201;i++){
			s11[i] = "."; s22[i] = ".";
		}
		int now1=0,now2=0;
		for(int i=0;i<(int)s1.length();i++){
			if(s1[i] == '"'){
				now1++;
				s11[now1] = "";
			}else s11[now1] += s1[i];
		}
		for(int i=0;i<(int)s2.length();i++){
			if(s2[i] == '"'){
				now2++;
				s22[now2] = "";
			}else s22[now2] += s2[i];
		}
		int d=0;
        int maxnow;
        if(now1 < now2) maxnow = now2;
        else maxnow = now1;
		for(int i=0;i<maxnow+1;i++){
			if(s11[i] != s22[i]){
				if(i&1){
					d++;
				}else d+=2;
			}
		}
		if(d==0)cout<<"IDENTICAL";
		else if(d==1)cout<<"CLOSE";
		else cout<<"DIFFERENT";
		cout<<"\n";
	}
}

C++: #include<iostream>
#include<vector>
#include<cmath>
#include<algorithm>
#include<utility>
#include<map>
#include<set>
#include<string>

using namespace std;
#define ll long long

bool check(string s1,string s2){
    int l = 0, r = 0;
    bool flag = false;
    int cnt = 0;
    while(l < s1.size() || r < s2.size()){
        if(s1.size() == l || s2.size() == r)return false;
        if(s1[l] != s2[r])return false;
        if(s1[l] == '"'){
            l++;
            string ss;
            while(s1[l]!='"'){
                ss += s1[l];
                l++;
            }
            l++;
            r++;
            string ss2;
            while(s2[r]!='"'){
                ss2 += s2[r];
                r++;
            }
            r++;
            if(ss != ss2)cnt++;
        }else{
            l++;
            r++;
        }
    }
    return (l == s1.size() && r == s2.size() && cnt <= 1);
}
 
int main(){
    while(1){
        string s1,s2;
        cin >> s1;
        if(s1==".")break;
        cin >> s2;
        if(s1 == s2){
            cout <<"IDENTICAL" << endl;
        }else{
            if(check(s1,s2)){
                cout << "CLOSE" << endl;
            }else{
                cout << "DIFFERENT" << endl;
            }
        }
    }
    return 0;
}

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

using namespace std;

int main()
{
  while(1){
    string row1,row2;
    string period(".");
    string cover("\"");
    string none("");

    cin>>row1;
    if(row1 == period){
      break;
    }
    cin>>row2;

    if(row1 == row2){
      cout<<"IDENTICAL"<<endl;
    }
    else{
      int size1 = row1.size();
      vector<string> Row1;
      string temp1;

      for(int i = 0;i < size1;++i){ 
        char s = row1[i];
        if(s == '\"'){
          Row1.push_back(temp1);
          temp1.clear();
        }
        else if(i == size1 - 1 && s != '\"'){
          temp1 += row1[i];
          Row1.push_back(temp1);
        }
        else{
          temp1 += row1[i];
        }
      }

      int size2 = row2.size();
      vector<string> Row2;
      temp1.clear();

      for(int i = 0;i < size2;++i){ 
        char s = row2[i];
        if(s == '\"'){
          Row2.push_back(temp1);
          temp1.clear();
        }
        else if(i == size2 - 1 && s != '\"'){
          temp1 += row2[i];
          Row2.push_back(temp1);
        }
        else{
          temp1 += row2[i];
        }
      }

      int Size1 = Row1.size();
      int Size2 = Row2.size();
      int count = 0;

      if(Size1 != Size2){
        cout<<"DIFFERENT"<<endl;
      }
      else{
        for(int i = 0;i <= Size1;++i){
          string check1,check2;
          check1 = Row1[i];
          check2 = Row2[i];

          if(i % 2 == 0){
            if(check1 != check2){
              cout<<"DIFFERENT"<<endl;
              break;
            }
          }
          else{
            if(check1 != check2){
              ++count;
            }
          }
          
          if(count == 2){
            cout<<"DIFFERENT"<<endl;
            break;
          }
        }
      }

      if(count == 1){
        cout<<"CLOSE"<<endl;
      }
    }
  }
  
  return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<numeric>
#include<vector>
#include <string>
using namespace std;

void split(string s, vector<string> &v){
    v.clear();
    s +='"';
    string str="";
    for(int i=0;i<s.size();i++){
        if(s[i]=='"'){
            v.push_back(str);
            str="";
        }
        else{
            str+=s[i];
        }
    }
}
int main(){
    while(1){
        string s1,s2; cin >>s1;
        if(s1==".")break;
        cin >> s2;
        if(s1==s2){
            cout << "IDENTICAL"<< endl;
        }
        else{
            vector<string> v1,v2;
            split(s1,v1);
            split(s2,v2);
            if(v1.size()!=v2.size()){
                cout << "DIFFERENT" << endl;
            }
            else{
                bool a=false;
                int cnt=0;
                for(int i=0;i<v1.size();i++){
                    if(i%2==0){
                        if(v1[i]!=v2[i])a=true;
                    }
                    else{
                        if(v1[i]!=v2[i])cnt++;
                    }
                }
                if(a){
                    cout << "DIFFERENT" << endl;
                }
                else if(cnt>1){
                    cout << "DIFFERENT" << endl;
                }
                else{
                    cout << "CLOSE" << endl;
                }
            }
        }
    }
}