foo.cc: In function 'int main()':
foo.cc:4:9: error: 'cout' was not declared in this scope
  n%m==0?cout<<n/m:cout<<n/m+1;
         ^~~~
foo.cc:4:9: note: suggested alternative:
In file included from foo.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   'std::cout'
   extern ostream cout;  /// Linked to standard output
                  ^~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。