Language: C++

#include<bits/stdc++.h>
using namespace
 
int main(){
    int a,b;
    cin>>a>>b;
    while(a!=0){
        if(a<b) swap(a,b);
        a%=b;
    }cout<<b<<endl;
    return 0;
}


Compiler output:
a.cc:4:1: error: expected identifier before 'int'
    4 | int main(){
      | ^~~
a.cc:2:16: error: expected ';' before 'int'
    2 | using namespace
      |                ^
      |                ;
    3 | 
    4 | int main(){
      | ~~~             
a.cc: In function 'int main()':
a.cc:6:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |     cin>>a>>b;
      |     ^~~
      |     std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 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:8:17: error: 'swap' was not declared in this scope
    8 |         if(a<b) swap(a,b);
      |                 ^~~~
a.cc:8:17: note: suggested alternatives:
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181:
/usr/include/c++/14/bits/regex.h:2230:5: note:   'std::__cxx11::swap'
 2230 |     swap(match_results<_Bi_iter, _Alloc>& __lhs,
      |     ^~~~
In file included from /usr/include/c++/14/bits/stl_pair.h:61,
                 from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/move.h:226:5: note:   'std::swap'
  226 |     swap(_Tp& __a, _Tp& __b)
      |     ^~~~
/usr/include/c++/14/bits/move.h:226:5: note:   'std::swap'
In file included from /usr/include/c++/14/exception:166,
                 from /usr/include/c++/14/stdexcept:38,
                 from /usr/include/c++/14/system_error:43,
                 from /usr/include/c++/14/bits/ios_base.h:46,
                 from /usr/include/c++/14/streambuf:43,
                 from /usr/include/c++/14/bits/streambuf_iterator.h:35,
                 from /usr/include/c++/14/iterator:66,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:54:
/usr/include/c++/14/bits/exception_ptr.h:229:5: note:   'std::__exception_ptr::swap'
  229 |     swap(exception_ptr& __lhs, exception_ptr& __rhs)
      |     ^~~~
In file included from /usr/include/c++/14/filesystem:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:200:
/usr/include/c++/14/bits/fs_path.h:736:15: note:   'std::filesystem::__cxx11::swap'
  736 |   inline void swap(path& __lhs, path& __rhs) noexcept { __lhs.swap(__rhs); }
      |               ^~~~
a.cc:10:6: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   10 |     }cout<<b<<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:10:15: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   10 |     }cout<<b<<endl;
      |               ^~~~
      |               std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~