foo.cpp:2:7: error: expected nested-name-specifier before 'spacename'
 using spacename std;
       ^
foo.cpp: In function 'int main()':
foo.cpp:6:5: error: 'cin' was not declared in this scope
     cin >>x>>y;
     ^
foo.cpp:6:5: note: suggested alternative:
In file included from foo.cpp:1:0:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/iostream:60:18: note:   'std::cin'
   extern istream cin;  /// Linked to standard input
                  ^
foo.cpp:8:5: error: 'cout' was not declared in this scope
     cout <<sum<<endl;
     ^
foo.cpp:8:5: note: suggested alternative:
In file included from foo.cpp:1:0:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^
foo.cpp:8:17: error: 'endl' was not declared in this scope
     cout <<sum<<endl;
                 ^
foo.cpp:8:17: note: suggested alternative:
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/iostream:39:0,
                 from foo.cpp:1:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ostream:564:5: note:   'std::endl'
     endl(basic_ostream<_CharT, _Traits>& __os)
     ^