Maximum Difference Between Array Elements

You are given an array of integers. Your task is to compute the maximum difference (\Delta = a_j - a_i) between any two elements such that the larger element (a_j) appears after the smaller element (a_i) in the array. If no such pair exists, return 0.

Formally, given an array (a) of length (n), find: [ \max_{0 \leq i < j < n} (a_j - a_i), ] with the condition that if (a_j \leq a_i) for every (j > i), then the answer is 0.

The problem simulates real-time analysis of data where you try to capture the largest positive change in a sequence.

inputFormat

The input is read from standard input (stdin) and consists of two lines:

• The first line contains a single integer (n) representing the number of elements in the array. (n) can be zero.
• The second line (if (n > 0)) contains (n) space-separated integers representing the elements of the array.

outputFormat

Output a single integer to standard output (stdout) which is the maximum difference as defined by the problem. If the array is empty or no valid pair exists, output 0.## sample

6
7 1 5 3 6 4

5