import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int maxValue = -1999999999;
		int min = sc.nextInt();
		for(int i = 1; i < n; i++) {
			int nowNum = sc.nextInt();
			int maxValueCandidate = nowNum - min;
			if (maxValue < maxValueCandidate) {
				maxValue = maxValueCandidate;
			}
			if(min > nowNum) {
				min = nowNum;
			}
		}
		sc.close();
		System.out.println(maxValue);
	}
}
/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