Language: C++

#include <bits/stdc++.h>
using namespace stdl;

int main(){
  string s;
  cin >> s;
  if (s == "SAT"){
    cout << 1 << endl;
  }
  if (s == "FRI"){
    cout << 2 << endl;
  }
  if (s == "THU"){
    cout << 3 << endl;
  }
  if (s == "WED"){
    cout << 4 << endl;
  }
  if (s == "TUE"){
    cout << 5 << endl;
  }
  if (s == "MON"){
    cout << 6 << endl;
  }
  if (s == "SUN"){
    cout << 7 << endl;
  }
}

Compiler output:
a.cc:2:17: error: 'stdl' is not a namespace-name
    2 | using namespace stdl;
      |                 ^~~~
a.cc: In function 'int main()':
a.cc:5:3: error: 'string' was not declared in this scope
    5 |   string s;
      |   ^~~~~~
a.cc:5:3: note: suggested alternatives:
In file included from /usr/include/c++/14/string:41,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> s;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:10: error: 's' was not declared in this scope
    6 |   cin >> s;
      |          ^
a.cc:8:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |     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:8:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    8 |     cout << 1 << 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)
      |     ^~~~
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:11:18: 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:14:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   14 |     cout << 3 << 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:14:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   14 |     cout << 3 << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:17:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   17 |     cout << 4 << 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:17:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   17 |     cout << 4 << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:20:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   20 |     cout << 5 << 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:20:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   20 |     cout << 5 << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:23:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   23 |     cout << 6 << 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:23:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   23 |     cout << 6 << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:26:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   26 |     cout << 7 << 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:26:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   26 |     cout << 7 << endl;
      |                  ^~~~
      |                  std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~