Happy 5th birthday, Cody! Since 5 is a prime number, let's have some fun looking for other prime numbers.
Given a positive integer x, find the nearest prime number. Keep in mind that the nearest prime may be less than x.
nearestprime(5) = 5 nearestprime(36) = 37 nearestprime(200) = 199
NOTE: You may ignore cases in which two prime numbers are equally close to x. (e.g., x=12 --> 11 and 13 are both primes).