Craigslist Phone Verification Sytem Clone

Recently, craigslist has set up a phone verification system that required a phone number and it uses that phone number to genorate a pin code using an algorithum. We are looking to have a program developed to accept the input of a phone number and output the pin code that craigslist needs. Meaning, the program will need to output the same pin code that craigslist needs to cerify the account. Your job is to figure out the algorythm craigslist is using and write a program that can take the input of a phone number and output the required craigslist pin. This project MUST be completed in 3 business days.