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<bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef pair<LL,LL> P;
const LL mod=1e9+7;
const LL LINF=1LL<<62;
const int INF=1<<17;

int main(){
    string s,t;
    while(cin >> s >> t){
        if(s==".") return 0;
        vector<string> p,q;
        string tmp="";
        for(int i=0;i<s.length();i++){
            if(s[i]=='"'){
                p.push_back(tmp);
                tmp="";
            }
            else tmp.push_back(s[i]);
        }
        p.push_back(tmp);
        tmp="";
        for(int i=0;i<t.length();i++){
            if(t[i]=='"'){
                q.push_back(tmp);
                tmp="";
            }
            else tmp.push_back(t[i]);
        }
        q.push_back(tmp);
        if(p.size()!=q.size()){
            puts("DIFFERENT");
            continue;
        }
        int u=0,v=0,c=0;
        while(u<p.size()){
            if(p[u]!=q[v]){
                if(u%2==0){
                    c=2;
                    break;
                }
                else{
                    c++;
                    u++,v++;
                }
            }
            else{
                u++,v++;
            }
        }
        if(c==0) puts("IDENTICAL");
        else if(c==1) puts("CLOSE");
        else puts("DIFFERENT");
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define INF 1e18
#define int long long
#define Rep(i, a, n) for (int i = (a); i < (n); i++)
#define Repr(i, n, a) for (int i = (n); i >= (a); i--)
#define rep(i, n) Rep(i, 0, n)
#define repr(i, n) Repr(i, n, 0)
#define all(a) (a).begin(), (a).end()
using namespace std;
typedef pair<int, int> P;
typedef pair<int, P> PP;
const int mod = 1000000007;

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    string s, t;
    while (1)
    {
        cin >> s;
        if (s == ".")
            break;
        cin >> t;
        vector<string> vs, vt;
        string tmp = "";
        rep(i, s.size())
        {
            tmp += s[i];
            if (tmp.size() > 1 && tmp[0] == '"' && tmp[tmp.size() - 1] == '"')
            {
                vs.push_back(tmp);
                tmp = "";
            }
            if (tmp[0] != '"' && s[i + 1] == '"')
            {
                vs.push_back(tmp);
                tmp = "";
            }
        }
        if (tmp != "")
            vs.push_back(tmp);
        tmp = "";
        rep(i, t.size())
        {
            tmp += t[i];
            if (tmp.size() > 1 && tmp[0] == '"' && tmp[tmp.size() - 1] == '"')
            {
                vt.push_back(tmp);
                tmp = "";
            }
            if (tmp[0] != '"' && t[i + 1] == '"')
            {
                vt.push_back(tmp);
                tmp = "";
            }
        }
        if (tmp != "")
            vt.push_back(tmp);
        // rep(i, vs.size()) cout << vs[i] << " ";
        // cout << endl;
        // rep(i, vt.size()) cout << vt[i] << " ";
        // cout << endl;
        if (vs.size() != vt.size())
        {
            cout << "DIFFERENT" << endl;
            continue;
        }
        int cnt = 0;
        rep(i, vs.size())
        {
            if (vs[i] == vt[i])
                continue;
            if (vs[i][0] == '"' && vt[i][0] == '"')
                cnt++;
            else
                cnt = 2;
        }
        if (cnt == 0)
            cout << "IDENTICAL" << endl;
        else if (cnt == 1)
            cout << "CLOSE" << endl;
        else
            cout << "DIFFERENT" << endl;
    }
}

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

using namespace std;

int main()
{
  while(1){
    string row1,row2;
    string period(".");
    string cover("\"");

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

    if(row1 == row2){
      cout<<"IDENTICAL"<<endl;
    }
    else{
      int size1 = row1.size();
      vector<string> Row1;
      int j = 0;
      string temp2;

      for(int i = 0;i < size1;++i){ 
        string temp1;
        temp1 = row1[i];
        if(temp1 == cover){
          string temp4;
          Row1.push_back(temp2);
          temp2 = temp4;
        }
        else if(i == size1 - 1){
          temp2 += temp1;
          Row1.push_back(temp2);
        }
        else{
          temp2 += temp1;
        }
      }

      int size2 = row2.size();
      vector<string> Row2;
      string temp3;

      for(int i = 0;i < size2;++i){ 
        string temp1;
        temp1 = row2[i];
        if(temp1 == cover){
          string temp4;
          Row2.push_back(temp3);
          temp3 = temp4;
        }
        else if(i == size2 - 1){
          temp3 += temp1;
          Row2.push_back(temp3);
        }
        else{
          temp3 += temp1;
        }
      }

      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;
}