lassie% a.out
Sum the digits in an integer.
Enter a positive integer: -12
Positive integers only, please.
Enter a positive integer: 42
The sum of the digits is 6

lassie% a.out
Sum the digits in an integer.
Enter a positive integer: -32
Positive integers only, please.
Enter a positive integer: -0
Positive integers only, please.
Enter a positive integer: 0
Positive integers only, please.
Enter a positive integer: -20
Positive integers only, please.
Enter a positive integer: 21
The sum of the digits is 3
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