Prime Pair Sum

You are given a single integer X. Your task is to find a pair of prime numbers, p₁ and p₂, such that their sum equals X (i.e. \(p_1 + p_2 = X\)). If such a pair exists, output the pair in the format "p1 p2" (with a single space between them). If there is no such pair, print "Not possible".

The function should check for primes using an efficient algorithm. Recall that a prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

inputFormat

The input consists of a single integer X provided via stdin.

Example:

26

outputFormat

Output a single line to stdout containing either a valid pair of primes in the format "p1 p2" whose sum is X, or "Not possible" if no such pair exists.

Example:

3 23

26

3 23