Language: C++

#include <iostream>
using namesapce std;

int main(){
	int d; cin >> d;
  	if(d == 25) cout << "Christmas" << endl;
  else if(d == 24) cout << "Christmas Eve" << endl;
  else if(d == 23) cout << "Christmas Eve Eve" << endl;
  else if(d == 22) cout << "Christmas Eve Eve Eve" << endl;
 	return 0; 
}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namesapce'
    2 | using namesapce std;
      |       ^~~~~~~~~
a.cc: In function 'int main()':
a.cc:5:16: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |         int d; cin >> d;
      |                ^~~
      |                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:6:21: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |         if(d == 25) cout << "Christmas" << 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:6:44: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    6 |         if(d == 25) cout << "Christmas" << 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:7:20: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    7 |   else if(d == 24) cout << "Christmas Eve" << 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:7:47: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    7 |   else if(d == 24) cout << "Christmas Eve" << endl;
      |                                               ^~~~
      |                                               std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:8:20: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |   else if(d == 23) cout << "Christmas Eve Eve" << 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:8:51: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    8 |   else if(d == 23) cout << "Christmas Eve Eve" << endl;
      |                                                   ^~~~
      |                                                   std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:9:20: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |   else if(d == 22) cout << "Christmas Eve Eve Eve" << 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:9:55: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 |   else if(d == 22) cout << "Christmas Eve Eve Eve" << endl;
      |                                                       ^~~~
      |                                                       std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~