Language: C++

#include<iostream>
#include<sstream>
using namespace4 std;
int main(){
  	int r,g,b;
  	cin>>r>>g>>b;
  	stringstream s;
  	string rr,gg,bb;
  	s<<r;
  	s>>rr;
  	s<<b;
  	s>>bb;
  	s<<g;
  	s>>gg;
  	string ss="";
  	ss+=rr;
  	ss+=gg;
  	ss+=bb;
  	int res;
  	s<<ss;
  	s>>res;
  	if(res%4==0) cout<<"YES"<<endl;
  	else cout<<"NO"<<endl;
	return 0;
}

Compiler output:
a.cc:3:7: error: expected nested-name-specifier before 'namespace4'
    3 | using namespace4 std;
      |       ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |         cin>>r>>g>>b;
      |         ^~~
      |         std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:7:9: error: 'stringstream' was not declared in this scope; did you mean 'std::stringstream'?
    7 |         stringstream s;
      |         ^~~~~~~~~~~~
      |         std::stringstream
In file included from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/iosfwd:158:41: note: 'std::stringstream' declared here
  158 |   typedef basic_stringstream<char>      stringstream;
      |                                         ^~~~~~~~~~~~
a.cc:8:9: error: 'string' was not declared in this scope
    8 |         string rr,gg,bb;
      |         ^~~~~~
a.cc:8:9: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:9:9: error: 's' was not declared in this scope
    9 |         s<<r;
      |         ^
a.cc:10:12: error: 'rr' was not declared in this scope; did you mean 'r'?
   10 |         s>>rr;
      |            ^~
      |            r
a.cc:12:12: error: 'bb' was not declared in this scope; did you mean 'b'?
   12 |         s>>bb;
      |            ^~
      |            b
a.cc:14:12: error: 'gg' was not declared in this scope; did you mean 'g'?
   14 |         s>>gg;
      |            ^~
      |            g
a.cc:15:15: error: expected ';' before 'ss'
   15 |         string ss="";
      |               ^~~
      |               ;
a.cc:16:9: error: 'ss' was not declared in this scope
   16 |         ss+=rr;
      |         ^~
a.cc:22:22: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   22 |         if(res%4==0) cout<<"YES"<<endl;
      |                      ^~~~
      |                      std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:22:35: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   22 |         if(res%4==0) cout<<"YES"<<endl;
      |                                   ^~~~
      |                                   std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:23:14: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   23 |         else cout<<"NO"<<endl;
      |              ^~~~
      |              std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:23:26: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   23 |         else cout<<"NO"<<endl;
      |                          ^~~~
      |                          std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~