So this is a pretty complex problem. The easiest way is to start from your phone number then run operations in reverse (-7, +2, /3) to get to 0. It boils down to looking at the modulus base 3 of the number at each step. Subtracting 7 and adding 2 both reduce the modulus by 1. Every time the modulus is 0, it only takes one step to reduce the number.
Contact iNPUT-ACE Designed by certified forensic video analysts with over thirty years of experience. This powerful workflow engine has set new standards for the examination, processing, and presentation of video in criminal investigations. Certain platforms like tablets, or smartphones will pop-up only-numeric keyboard for this input field. It is hard to enforce particular regular expression through HTML because of variety of phone number formats used along with differences in country codes, and number separators.