foo.cc:1:1: error: 'include' does not name a type; did you mean '__has_include'?
 include <iostream>
 ^~~~~~~
 __has_include
foo.cc: In function 'int main()':
foo.cc:6:1: error: 'cin' was not declared in this scope
 cin>>x>>y;
 ^~~
foo.cc:6:1: note: suggested alternative: 'main'
 cin>>x>>y;
 ^~~
 main
foo.cc:7:1: error: 'cout' was not declared in this scope
 cout<<x+y;
 ^~~~