Language: C++

#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <deque>
#include <utility>
#include <algorithm>
using namespace std;

int main(void){
   
　string s1, s2;
　
　cin>>s1;
　cin>>s2;
　
　if(s1.size()==s2.size()){
　
　if(s1>s2){
　    cout<<"GREATER"<<endl;
　}else if(s1<s2){
　    cout<<"LESS"<<endl;
　}else{
　    cout<<"EQUAL"<<endl;
　}
　}else{
　    if(s1.size()>s2.size()){
　        cout<<"GREATER"<<endl;
　    }else{
　        cout<<"LESS"<<endl;
　    }
　    
　}
}


Compiler output:
a.cc:12:1: error: extended character 　 is not valid in an identifier
   12 | 　string s1, s2;
      | ^
a.cc:13:1: error: extended character 　 is not valid in an identifier
   13 | 　
      | ^
a.cc:14:1: error: extended character 　 is not valid in an identifier
   14 | 　cin>>s1;
      | ^
a.cc:15:1: error: extended character 　 is not valid in an identifier
   15 | 　cin>>s2;
      | ^
a.cc:16:1: error: extended character 　 is not valid in an identifier
   16 | 　
      | ^
a.cc:17:1: error: extended character 　 is not valid in an identifier
   17 | 　if(s1.size()==s2.size()){
      | ^
a.cc:18:1: error: extended character 　 is not valid in an identifier
   18 | 　
      | ^
a.cc:19:1: error: extended character 　 is not valid in an identifier
   19 | 　if(s1>s2){
      | ^
a.cc:20:1: error: extended character 　 is not valid in an identifier
   20 | 　    cout<<"GREATER"<<endl;
      | ^
a.cc:21:1: error: extended character 　 is not valid in an identifier
   21 | 　}else if(s1<s2){
      | ^
a.cc:22:1: error: extended character 　 is not valid in an identifier
   22 | 　    cout<<"LESS"<<endl;
      | ^
a.cc:23:1: error: extended character 　 is not valid in an identifier
   23 | 　}else{
      | ^
a.cc:24:1: error: extended character 　 is not valid in an identifier
   24 | 　    cout<<"EQUAL"<<endl;
      | ^
a.cc:25:1: error: extended character 　 is not valid in an identifier
   25 | 　}
      | ^
a.cc:26:1: error: extended character 　 is not valid in an identifier
   26 | 　}else{
      | ^
a.cc:27:1: error: extended character 　 is not valid in an identifier
   27 | 　    if(s1.size()>s2.size()){
      | ^
a.cc:28:1: error: extended character 　 is not valid in an identifier
   28 | 　        cout<<"GREATER"<<endl;
      | ^
a.cc:29:1: error: extended character 　 is not valid in an identifier
   29 | 　    }else{
      | ^
a.cc:30:1: error: extended character 　 is not valid in an identifier
   30 | 　        cout<<"LESS"<<endl;
      | ^
a.cc:31:1: error: extended character 　 is not valid in an identifier
   31 | 　    }
      | ^
a.cc:32:1: error: extended character 　 is not valid in an identifier
   32 | 　
      | ^
a.cc:33:1: error: extended character 　 is not valid in an identifier
   33 | 　}
      | ^
a.cc: In function 'int main()':
a.cc:12:1: error: '\U00003000string' was not declared in this scope
   12 | 　string s1, s2;
      | ^~~~~~~~
a.cc:13:1: error: '\U00003000' was not declared in this scope
   13 | 　
      | ^~
a.cc:15:1: error: '\U00003000cin' was not declared in this scope
   15 | 　cin>>s2;
      | ^~~~~
a.cc:15:8: error: 's2' was not declared in this scope
   15 | 　cin>>s2;
      |        ^~
a.cc:16:3: error: expected ';' before '\U00003000if'
   16 | 　
      |   ^
      |   ;
   17 | 　if(s1.size()==s2.size()){
      | ~~~~
a.cc:26:4: error: 'else' without a previous 'if'
   26 | 　}else{
      |    ^~~~
a.cc:27:3: error: expected ';' before 'if'
   27 | 　    if(s1.size()>s2.size()){
      |   ^   ~~
      |   ;
a.cc:29:8: error: 'else' without a previous 'if'
   29 | 　    }else{
      |        ^~~~
a.cc:30:3: error: expected ';' before 'cout'
   30 | 　        cout<<"LESS"<<endl;
      |   ^       ~~~~
      |   ;
a.cc:31:3: error: expected ';' before '}' token
   31 | 　    }
      |   ^   ~
      |   ;
a.cc:32:3: error: expected ';' before '\U00003000'
   32 | 　
      |   ^
      |   ;
   33 | 　}
      | ~~