import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws Exception {

		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int min = 1000000000;
		int max = -1000000000;

		for(int i = 0; i < n; i++) {

			int r = sc.nextInt();

			if(i == 0) {

				min = r;

			} else {

				max = Math.max(max, r - min);
				min = Math.min(min, r);

			}
		}

		System.out.println(max);

	}

}

/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