Language: C++

#include <iostream>
#include <stdlib.h>
int main()
{
  int n;
  cin>>n;
  if(n>=400 && n<=599)
  {
    cout<<8;
  }
  if(n>=600 && n<=799)
  {
    cout<<7;
  }
  if(n>=800 && n<=999)
  {
    cout<<6;
  }
  if(n>=1000 && n<=1199)
  {
    cout<<5;
  }
  if(n>=1200 && n<=1399)
  {
    cout<<4;
  }
  if(n>1400 && n<1599)
  {
    cout<<3;
  }
  if(n>1600 && n<1799)
  {
    cout<<2;
  }
  if(n>1800 && n<1999)
  {
    cout<<1;
  }
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<<8;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:13:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   13 |     cout<<7;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:17:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   17 |     cout<<6;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:21:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   21 |     cout<<5;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:25:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   25 |     cout<<4;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:29:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   29 |     cout<<3;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:33:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   33 |     cout<<2;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:37:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   37 |     cout<<1;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~