foo.cc:3:7: error: expected nested-name-specifier before 'namepace'
 using namepace std;
       ^~~~~~~~
foo.cc: In function 'int main()':
foo.cc:7:5: error: 'cout' was not declared in this scope
     cout <<"A" << endl;
     ^~~~
foo.cc:7:5: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~
foo.cc:7:19: error: 'endl' was not declared in this scope
     cout <<"A" << endl;
                   ^~~~
foo.cc:7:19: note: suggested alternative:
In file included from /usr/include/c++/7/iostream:39:0,
                 from foo.cc:1:
/usr/include/c++/7/ostream:590:5: note:   'std::endl'
     endl(basic_ostream<_CharT, _Traits>& __os)
     ^~~~

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