import java.util.Scanner;

public class Main {
	
	//?????????????????????????????????????????????????????§?????¢???????????????
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int smallerNum = sc.nextInt();
		int maxDef = Integer.MIN_VALUE;
		
		for (int i = 0; i < num - 1; i++) {
			int j = sc.nextInt();
			maxDef = Math.max(maxDef, j - smallerNum);
			smallerNum = Math.min(smallerNum, j);
		}
		System.out.println(maxDef);
	}	
}
/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