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 INF 1e9

int w,h,sy,sx,gy,gx;
int field[30][30];
int dx[4]={1,0,-1,0},dy[4]={0,-1,0,1};

bool contain(int y,int x){
    return (0<=y && y<h && 0<=x && x<w);
}

int solve(int y,int x,int T,int F[30][30]){
    if(T>10)return T;

    int res=INF;

    for(int i=0;i<4;i++){
        int ny=y+dy[i],nx=x+dx[i];

        if(F[ny][nx]==1 || !contain(ny,nx))continue;

        bool f=false;

        while(1){
            ny+=dy[i];nx+=dx[i];

            if(!contain(ny,nx))break;
            if(F[ny][nx]==1){
                F[ny][nx]=0;
                f=true;
                break;
            }
        }

        ny-=dy[i];nx-=dx[i];

        if(ny==gy && nx==gx)res=T+1;
        else res=min(res,solve(ny,nx,T+1,F));

        if(f)F[ny+dy[i]][nx+dx[i]]=1;
        
    }

    return res;

}

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

    while(1){
        cin>>w>>h;

        if(w==0)break;

        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                cin>>field[i][j];

                if(field[i][j]==2){
                    sy=i;sx=j;
                }
                if(field[i][j]==3){
                    gy=i;gx=j;
                }
            }
        }

        int ans=solve(sy,sx,0,field);

        if(ans>10)ans=-1;

        cout<<ans<<endl;

    }

}

C++: #include <iostream>
#include <algorithm>
#include <string>
using namespace std;
string s1, s2;

int main() {

  while (1) {
    int count = 0;
    int n1 = 0;
    int n2 = 0;
    int error = 0;

    cin >> s1 >> s2;
    if(s1 == ".")
      break;

    if(s1 == s2) {
      cout << "IDENTICAL" << endl;
      continue;
    }
    else if(s1[n1] != s2[n2]) {
      cout << "DIFFERENT" << endl;
      continue;
    }

    while(1) {
      if(s1[n1] == '"' && s2[n2] == '"') {
        while(1) {
          if (s1[n1] != s2[n2]) count++;
          if(s1[n1] != '"') n1++;
          if(s2[n2] != '"') n2++;
          if (s1[n1] == '"' && s2[n2] == '"') {
            if(count > 0) error++;
            break;
          }
        }
      }
      if(n1 != s1.size()) n1++;
      if(n2 != s2.size()) n2++;
      if(n1 == s1.size() && n2 == s2.size())  {
        if (error >= 2 ) {
          cout << "DIFFERENT" << endl;
          break;
        }
        else {
          cout << "CLOSE" << endl;
          break;
        }
      }
    }
  }

  return 0;
}

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

int judge(string s1, string s2){
	int symbol1[200]={0}, symbol2[200]={0};
	int wrong=0, num1=0, num2=0, a;
	int first1=0, first2=0, end1, end2;
	int size = max(s1.size(), s2.size() );
	char j='\"';
	/* search " " */
	
	for(int i=0; i<size; i++){
		
		if(s1[i] == j){
			symbol1[num1++] = i;
		}
		if(s2[i] == j){
			symbol2[num2++] = i;
		}
	}
	
	a = 0;
	end1 = symbol1[a];
	end2 = symbol2[a];
	
	/* out of "" */
	
	int k;
	while(k=1){
		if(end1 - first1 != end2 - first2){
			wrong += 3;
			break;
		}
		
		for(int i=0; i<size; i++){
			if(end1 - first1 == 0 || end1 - first1 == 1){
				break;
			}
			if(s1[first1++] != s2[first2++]){
				wrong += 3;
				/*cout << s1[first1-1] <<" " << s2[first2-1]<<"\n";*/
			}
			if(i == end1 - first1){
				break;
			}
		}
		
		first1 = symbol1[++a];
		first2 = symbol2[a];
		end1 = symbol1[++a];
		end2 = symbol2[a];
		
		if(a == size || symbol1[a] == 0 || symbol2[a] == 0){
			break;
		}
	}
	
	/* in " " */
	
	a = 0;
	first1 = symbol1[a];
	first2 = symbol2[a];
	end1 = symbol1[++a];
	end2 = symbol2[a];
	
	while(k=1){
		for(int i=0; i<size; i++){
			
			if(end1 - first1 == 0 && end2 - first2 == 0){
				break;
			}
			
			if(end1 - first1 != end2 - first2){
				wrong += 1;
				break;
			}
			
			if(s1[first1++] != s2[first2++]){
				cout << s1[first1-1] <<" != " << s2[first2-1] << "\n";
				wrong += 1;
				break;
			}
			
			if(i == symbol1[a] - symbol1[a-1]){
				break;
			}
		}
		
		first1 = symbol1[++a];
		first2 = symbol2[a];
		end1 = symbol1[++a];
		end2 = symbol2[a];
		
		if(symbol1[a] == 0 || symbol2[a] == 0){
			break;
		}
	}
	return wrong;
}


int main(void){
	string st1, st2;
	int pi, d;
	
	for(int i=0; i<100; i++){
		for(int k=0; k<2; k++){
			if(k == 0){
				cin >> st1;
				if(st1 == "."){
					pi = 1;
					break;
				}
			}else{
				cin >> st2;
			}
		}
		
		if(pi == 1){
				break;
			}
		d = judge(st1, st2);
		
		if(d == 0){
			cout <<"IDENTICAL\n";
		}else if(d == 1){
			cout << "CLOSE\n";
		}else{
			cout << "DIFFERENT\n";
		}
	}
	
	return 0;
}