Language: C++

#include <bits/stdc++.h>
using namespase std;

int main(){
	int A,B;
  	string op;
  	cin >> A >> op >> B;
  	if(op == "+") cout << A+B <<endl;
  	else cout << A - B << endl;
}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namespase'
    2 | using namespase std;
      |       ^~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:9: error: 'string' was not declared in this scope
    6 |         string op;
      |         ^~~~~~
a.cc:6:9: 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:7:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |         cin >> A >> op >> B;
      |         ^~~
      |         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:7:21: error: 'op' was not declared in this scope
    7 |         cin >> A >> op >> B;
      |                     ^~
a.cc:8:23: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |         if(op == "+") cout << 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:8:37: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    8 |         if(op == "+") cout << A+B <<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:9:14: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |         else cout << 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:9:31: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 |         else cout << A - B << endl;
      |                               ^~~~
      |                               std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~