View Compilation Error

0_0_39648086_49.cpp:2:7: error: expected nested-name-specifier before 'spacename'
    2 | using spacename std;
      |       ^~~~~~~~~
0_0_39648086_49.cpp: In function 'int main()':
0_0_39648086_49.cpp:6:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |         cin>>n;
      |         ^~~
      |         std::cin
In file included from 0_0_39648086_49.cpp:1:
gcc-13.1.0/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
0_0_39648086_49.cpp:12:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |         cout<<sum;
      |         ^~~~
      |         std::cout
gcc-13.1.0/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~