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;
int main(){
  while (1){
    string s1;
    cin >> s1;
    if (s1 == "."){
      break;
    }
    string s2;
    cin >> s2;
    if (s1 == s2){
      cout << "IDENTICAL" << endl;
    } else {
      int N = s1.size();
      vector<string> A(1);
      for (int i = 0; i < N; i++){
        if (s1[i] == '"'){
          A.push_back("");
        } else {
          A.back().push_back(s1[i]);
        }
      }
      int M = s2.size();
      vector<string> B(1);
      for (int i = 0; i < M; i++){
        if (s2[i] == '"'){
          B.push_back("");
        } else {
          B.back().push_back(s2[i]);
        }
      }
      if (A.size() != B.size()){
        cout << "DIFFERENT" << endl;
      } else {
        bool ok = true;
        int cnt = 0;
        int K = A.size();
        for (int i = 0; i < K; i++){
          if (A[i] != B[i]){
            if (i % 2 == 0){
              ok = false;
            } else {
              cnt++;
            }
          }
        }
        if (!ok || cnt >= 2){
          cout << "DIFFERENT" << endl;
        } else {
          cout << "CLOSE" << endl;
        }
      }
    }
  }
}

C++: #include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1 << 28;
constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	int kkt = 89;
	while (kkt) {
		string s; cin >> s; if (s == ".") break;
		string t; cin >> t;
		if (s == t) puts("IDENTICAL");
		else {
			
			vector<string> vs, vt, ss, tt;
			string tmp;
			string tmp2;
			{
				bool flag = false;
				for (int i = 0; i < s.size(); i++) {
					if (s[i] == '"') {
						if (!flag) {
							flag = true;
							ss.push_back(tmp2);
							tmp2 = "";
						}
						else {
							flag = false;
							vs.push_back(tmp);
							tmp = "";
						}
					}
					else {
						if (flag) tmp += s[i];
						else tmp2 += s[i];
					}
				}
			}
			ss.push_back(tmp2);
			tmp2 = "";
			{
				bool flag = false;
				for (int i = 0; i < t.size(); i++) {
					if (t[i] == '"') {
						if (!flag) {
							flag = true;
							tt.push_back(tmp2);
							tmp2 = "";
						}
						else {
							flag = false;
							vt.push_back(tmp);
							tmp = "";
						}
					}
					else {
						if (flag) tmp += t[i];
						else tmp2 += t[i];
					}
				}
			}
			tt.push_back(tmp2);
			//for (int i = 0; i < ss.size(); i++) cout << ss[i] << " " << tt[i] << endl;
			if (ss != tt || vs.size() != vt.size()) puts("DIFFERENT");
			else {
				int cnt = 0;
				for (int i = 0; i < vs.size(); i++) {
					if (vs[i] != vt[i]) cnt++;
				}
				if (cnt >= 2) puts("DIFFERENT");
				else puts("CLOSE");
			}
		}
	}
	return 0;

}

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

int main()
{
	while(true){
		string s1;
		cin >> s1;

		if(s1==".")
			break;

		string s2;
		cin >> s2;

		if(s1==s2){
			cout << "IDENTICAL" << endl;
			continue;
		}

		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('\"');
			t2.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++: #include <iostream>
using namespace std;

int main(){
	while(1){
		string s1,s2;
		cin >> s1;
		if(s1==".")break;
		cin >> s2;

		if(s1==s2){
			cout << "IDENTICAL" << endl;
			continue;
		}

		string t1,t2;
		t1 = s1;t2 = s2;
		while(1){
			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('\"');
			t2.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 << "DIFFERENR" << endl;
		}
	}
	return 0;
}