/in/foo.cc: In function 'int main()':
/in/foo.cc:39:15: error: expected unqualified-id before '<<' token
  ostringstream<<fixed<<setprecision(2)<<bill;
               ^~
/in/foo.cc:40:26: error: expected primary-expression before '.' token
  string ans=ostringstream.str();
                          ^