Language: C++

#include<iostream>
using namespacestd;

int main(){
   int a, b, c;
   cin >> a >> b >> c;

   if(a << b << c){
      cout<< "a" <<" "<< "b" <<" "<< "c" <<endl;
   }

   if(a >> b >> c){
      cout<< "c" <<" "<< "b" <<" "<< "a" <<endl;
   }

   if(a << b, a << c, b >> c){
      cout<< "a" <<" "<< "c" <<" "<< "b" <<endl;
   }

   if(a >> b, a << c, b << c){
      cout<< "b" <<" "<< "a" <<" "<< "c" <<endl;
   }

   if(a >> b, a >> c, b << c){
      cout<< "b" <<" "<< "c" <<" "<< "a" <<endl;
   }

   if(a << b, a >> c, b >> c){
      cout<< "c" <<" "<< "a" <<" "<< "b" <<endl;
   }
   return 0;
}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namespacestd'
    2 | using namespacestd;
      |       ^~~~~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:4: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |    cin >> a >> b >> c;
      |    ^~~
      |    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:9:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |       cout<< "a" <<" "<< "b" <<" "<< "c" <<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:9:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 |       cout<< "a" <<" "<< "b" <<" "<< "c" <<endl;
      |                                            ^~~~
      |                                            std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:13:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   13 |       cout<< "c" <<" "<< "b" <<" "<< "a" <<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:13:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   13 |       cout<< "c" <<" "<< "b" <<" "<< "a" <<endl;
      |                                            ^~~~
      |                                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:17:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   17 |       cout<< "a" <<" "<< "c" <<" "<< "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:17:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   17 |       cout<< "a" <<" "<< "c" <<" "<< "b" <<endl;
      |                                            ^~~~
      |                                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:21:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   21 |       cout<< "b" <<" "<< "a" <<" "<< "c" <<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:21:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   21 |       cout<< "b" <<" "<< "a" <<" "<< "c" <<endl;
      |                                            ^~~~
      |                                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:25:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   25 |       cout<< "b" <<" "<< "c" <<" "<< "a" <<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:25:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   25 |       cout<< "b" <<" "<< "c" <<" "<< "a" <<endl;
      |                                            ^~~~
      |                                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:29:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   29 |       cout<< "c" <<" "<< "a" <<" "<< "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:29:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   29 |       cout<< "c" <<" "<< "a" <<" "<< "b" <<endl;
      |                                            ^~~~
      |                                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~