| Problem G: Simply Emirp |
An integer greater than 1 is called a prime number if its only positive divisors (factors) are 1 and itself. Prime numbers have been studied over the years by a lot of mathematicians. Applications of prime numbers arise in Cryptography and Coding Theory among others.
Have you tried reversing a prime ? For most primes, you get a composite (43 becomes 34). An Emirp (Prime spelt backwards) is a Prime that gives you a different Prime when its digits are reversed. For example, 17 is Emirp because 17 as well as 71 are Prime. In this problem, you have to decide whether a number N is Non-prime or Prime or Emirp. Assume that 1< N< 1000000.
Interestingly, Emirps are not new to NTU students. We have been boarding 199 and 179 buses for quite a long time!
Input consists of several lines specifying values for N.
For each N given in the input, output should contain one of the following:
1. "N is not prime.",
if N is not a Prime number.
2. "N is prime.",
if N is Prime and N is not Emirp.
3. "N is emirp.",
if N is Emirp.
17 18 19 179 199
17 is emirp. 18 is not prime. 19 is prime. 179 is emirp. 199 is emirp.