/in/foo.cc: In member function 'numbers numbers::operator/(numbers)':
/in/foo.cc:128:2: warning: no return statement in function returning non-void [-Wreturn-type]
  }
  ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:136:11: error: no matching function for call to 'numbers::input()'
   a.input();
           ^
/in/foo.cc:20:10: note: candidate: numbers numbers::input(numbers&)
  numbers input(numbers &num)
          ^~~~~
/in/foo.cc:20:10: note:   candidate expects 1 argument, 0 provided
/in/foo.cc:137:11: error: no matching function for call to 'numbers::input()'
   b.input();
           ^
/in/foo.cc:20:10: note: candidate: numbers numbers::input(numbers&)
  numbers input(numbers &num)
          ^~~~~
/in/foo.cc:20:10: note:   candidate expects 1 argument, 0 provided
/in/foo.cc:139:12: error: no matching function for call to 'numbers::output()'
   c.output();
            ^
/in/foo.cc:32:10: note: candidate: numbers numbers::output(numbers, char)
  numbers output(const numbers num,char end='\n')
          ^~~~~~
/in/foo.cc:32:10: note:   candidate expects 2 arguments, 0 provided