It will still work even if there are five substrings, as long as there is
only one number string. The code would still be breaking the string into
three parts, what is before the number, the number and what is after the
number. The stuff before and after the number may be able to be divided into
substrings, but the key to the splitting is the number. So you are only
talking about a maximum of three strings. The verification will still work
even if the number is the only thing in the string.