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;
#define int long long
using ll=long long;
using vi=vector<int>;
using vl=vector<long long>;
using pii=pair<int,int>;
using pll=pair<long long,long long>;
#define ITR(i,c) for(auto i=begin(c);i!=end(c);++i)
#define FORE(x,c) for(auto &x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define REPW(i,n) for(i=0;i<(int)(n);++i)
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define OUTOFRANGE(y,x,h,w) (y<0||x<0||y>=h||x>=w)
#define dump(...)
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template<class T> ostream& operator << (ostream &os,const vector<T> &v) {
    ITR(i,v) os << *i << (i==end(v)-1 ? "" : " "); return os; }
template<class T> istream& operator >> (istream &is,vector<T> &v) {
    ITR(i,v) is >> * i; return is; }
template<class T> istream& operator >> (istream &is, pair<T,T> &p) {
        is >> p.first >> p.second; return is; }
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return 1;}return 0;}
//------------------------------------------------------------------------------
struct before_main_function {
    before_main_function() {
        #ifdef int
            #undef INF
            #define INF INFLL
            #define stoi stoll
        #endif
        cin.tie(0);ios::sync_with_stdio(false);
        cout<<setprecision(15)<<fixed;
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

int same(string a,string b) {
    vector<string> A,B,C,D;
    string tmp="";
    string tmp2="";
    int cnt=0;
    REP(i,SZ(a)) {
        if(a[i]=='"') {
            cnt++;
            if(cnt%2==0) {
                A.push_back(tmp);
                tmp="";
            }
            else {
                C.push_back(tmp2);
            }
        }
        else {
            if(cnt%2==0) {
                tmp2+=a[i];
            }
            else {
                tmp+=a[i];
            }
        }
    }
    tmp=tmp2="";
    REP(i,SZ(b)) {
        if(b[i]=='"') {
            cnt++;
            if(cnt%2==0) {
                B.push_back(tmp);
                tmp="";
            }
            else {
                D.push_back(tmp2);
            }
        }
        else {
            if(cnt%2==0) {
                tmp2+=b[i];
            }
            else {
                tmp+=b[i];
            }
        }
    }

    if(SZ(A)!=SZ(B)) return 0;
    if(SZ(C)!=SZ(D)) return 0;
    REP(i,SZ(C)) {
        if(C[i]!=D[i]) return 0;
    }

    cnt=0;
    REP(i,SZ(A)) {
        if(A[i]!=B[i]) cnt++;
    }
    if(cnt==0) {
        return 1;
    }
    else if(cnt==1) {
        return 2;
    }
    else {
        return 0;
    }
}
signed main() {
    while(1) {
        string s1,s2;
        cin>>s1;
        if(s1==".") break;
        cin>>s2;
        int res=same(s1,s2);
        if(res==0) cout<<"DIFFERENT"<<endl;
        else if(res==1) cout<<"IDENTICAL"<<endl;
        else cout<<"CLOSE"<<endl;
    }
    return 0;
}

C++: #include<iostream>

using namespace std;

int main(){

  char s1[200]={};
  char s2[200]={};
  char t1[200]={};
  char t2[200]={};
  char u1[200]={};
  char u2[200]={};

  int c=0,flag=0,j=0,k=0,l=0;

  cin>>s1>>s2;
 
  for(int i=0;i<200;i++){
    if(s1[i]=='"'){
      if(flag==0){
	flag=1;
	
      }else if(flag==1){
	flag=0;
	
      }
    }

    if(flag==1){
      t1[j]=s1[i];
      j++;    
    }

    if(flag==0){
      u1[l]=s1[i];
      l++;    
    }


  }
  j=0;
  l=0;
 for(int i=0;i<200;i++){

    if(s2[i]=='"'){
      if(flag==0){
	flag=1;
	
      }else if(flag==1){
	flag=0;
	
      }
    }

    if(flag==1){
      t2[j]=s2[i];
      j++;
    }

 if(flag==0){
      u2[l]=s2[i];
      l++;
    }

  }
 j=0;
 flag=0;

 /* cout<<t1<<endl;
 cout<<t2<<endl;
 cout<<u1<<endl;
 cout<<u2<<endl;*/

 //kyuukei~~~

   
  for(int i=0;i<150;i++){


    if(flag==1){
    if(t1[j]!=t2[k]){
      c++;
      flag=0;
    }

    if(t1[j]=='"' && t2[k]!='"'){
      j--;
    }
    if(t2[k]=='"' && t1[j]!='"'){
      k--;
    }

    j++;
    k++;

    }

   if(t1[j]=='"' && t2[k]=='"'){
     flag=1;

    }


  }

  for(int i=0;i<200;i++){
    if(u1[i]!=u2[i]){
      c=2;
    }
  }

    if(c==0){
      cout<<"IDENTICAL"<<endl;
    }else if(c==1){
      cout<<"CLOSE"<<endl;
    }else{
      cout<<"DIFFERENT"<<endl;
    }
  
return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

int main()
{
  string S, T;
  while(cin >> S, S != ".") {
    cin >> T;
    int beet = 0;
    string latte, malta;
    vector< string > oi, ushi;
    for(int i = 0; i < S.size(); i++) {
      if(beet % 2 == 0) latte += S[i], oi.push_back("");
      else oi.back() += S[i];
      if(S[i] == '\"') ++beet;
    }
    beet = 0;
    for(int i = 0; i < T.size(); i++) {
      if(beet % 2 == 0) malta += T[i], ushi.push_back("");
      else ushi.back() += T[i];
      if(T[i] == '\"') ++beet;
    }
    int incorrect = 0;
    if(oi.size() != ushi.size()) incorrect = 114514;
    for(int i = 0; i < oi.size(); i++) incorrect += oi[i] != ushi[i];

    if(latte != malta || incorrect >= 2) {
      cout << "DIFFERENT" << endl;
    } else if(S == T) {
      cout << "IDENTICAL" << endl;
    } else {
      cout << "CLOSE" << endl;
    }
  }
}