/in/foo.cc: In function 'int main()':
/in/foo.cc:5:1: error: 'cin' was not declared in this scope
cin>>a;
^~~
/in/foo.cc:5:1: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:60:18: note: 'std::cin'
extern istream cin; /// Linked to standard input
^~~
/in/foo.cc:10:1: error: 'cout' was not declared in this scope
cout<<b<<endl;
^~~~
/in/foo.cc:10:1: note: suggested alternative:
In file included from /in/foo.cc:1:0:
/usr/include/c++/6/iostream:61:18: note: 'std::cout'
extern ostream cout; /// Linked to standard output
^~~~
/in/foo.cc:10:10: error: 'endl' was not declared in this scope
cout<<b<<endl;
^~~~
/in/foo.cc:10:10: note: suggested alternative:
In file included from /usr/include/c++/6/iostream:39:0,
from /in/foo.cc:1:
/usr/include/c++/6/ostream:590:5: note: 'std::endl'
endl(basic_ostream<_CharT, _Traits>& __os)
^~~~