Prime Difference

You are given a list of integers and its length n. Your task is to compute the difference between the largest prime number and the smallest prime number present in the list. A prime number is defined as an integer greater than 1 that has no divisors other than 1 and itself. Formally, a number \(p\) is prime if \(p > 1\) and for any integer \(d\) such that \(2 \leq d \leq \sqrt{p}\), \(p \mod d \neq 0\).

If the list does not contain any prime numbers, output -1. If there is exactly one prime number in the list, the difference is defined as 0 (since \(p - p = 0\)).

inputFormat

The input is given from standard input (stdin) with the following format:

• The first line contains an integer n indicating the number of elements in the list.
• If n > 0, the second line contains n space-separated integers representing the elements of the list.

If n equals 0, there will be no second line.

outputFormat

Print a single integer to standard output (stdout): the difference between the largest and smallest prime numbers in the list. If there are no primes, output -1. If there is exactly one prime number, output 0.

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