Language: C++

#include <iostream>

int main()
{
  int n;
  cin>>n;

  if(n==0){
    cout<<"1"<<endl;
  }else if(n==1){
    cout<<"2"<<endl;
  }else if(n==2){
    cout<<"1"<<endl;
  }else{
    cout<<"0"<<endl;

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin>>n;
      |   ^~~
      |   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:9:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |     cout<<"1"<<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:9:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 |     cout<<"1"<<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:11:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |     cout<<"2"<<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:11:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   11 |     cout<<"2"<<endl;
      |                ^~~~
      |                std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:13:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   13 |     cout<<"1"<<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:13:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   13 |     cout<<"1"<<endl;
      |                ^~~~
      |                std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:15:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   15 |     cout<<"0"<<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:15:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   15 |     cout<<"0"<<endl;
      |                ^~~~
      |                std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:18:2: error: expected '}' at end of input
   18 | }
      |  ^
a.cc:4:1: note: to match this '{'
    4 | {
      | ^