+ import std.math;
  import std.typecons;
- import std.math;
  /*
- 
-     Write a function count_nums which takes an array of integers and returns
? ----

+ Write a function count_nums which takes an array of integers and returns
-     the number of elements which has a sum of digits > 0.
? ----

+ the number of elements which has a sum of digits > 0.
-     If a number is negative, then its first signed digit will be negative:
? ----

+ If a number is negative, then its first signed digit will be negative:
-     e.g. -123 has signed digits -1, 2, and 3.
? ----

+ e.g. -123 has signed digits -1, 2, and 3.
-     >>> count_nums([])
? ----

+ >>> count_nums([])
-     0L
+ 0L
-     >>> count_nums([-1L, 11L, -11L])
? ----

+ >>> count_nums([-1L, 11L, -11L])
-     1L
+ 1L
-     >>> count_nums([1L, 1L, 2L])
? ----

+ >>> count_nums([1L, 1L, 2L])
+ 3L
-     3L
-     
  */
  long count_nums(long[] arr)