import java.util.Scanner;

public class Main {
	
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
	    int n = scan.nextInt();
	    int[] r = new int[n];
	    for (int i = 0; i < n; i++) {
			r[i] = scan.nextInt();
		}
	  
	    int min = r[0];
		int margin = r[1] - r[0];
		for (int i = 1; i < r.length; i++) {
			margin = Math.max(margin, r[i] - min);
			min = Math.min(min, r[i]);
		}
		
		System.out.println(margin);
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz