/in/foo.cc: In function 'int main()':
/in/foo.cc:8:3: error: 'cin' was not declared in this scope
   cin>>a>>b;
   ^~~
/in/foo.cc:9:3: error: 'cout' was not declared in this scope
   cout<<fixed<<setprecision(8)<<a+b<< endl;
   ^~~~
/in/foo.cc:9:9: error: 'fixed' was not declared in this scope
   cout<<fixed<<setprecision(8)<<a+b<< endl;
         ^~~~~
/in/foo.cc:9:30: error: 'setprecision' was not declared in this scope
   cout<<fixed<<setprecision(8)<<a+b<< endl;
                              ^
/in/foo.cc:9:39: error: 'endl' was not declared in this scope
   cout<<fixed<<setprecision(8)<<a+b<< endl;
                                       ^~~~