import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int n = Integer.parseInt(sc.next()); // ?¨?????????°

		int minv = 0, maxv = Integer.MIN_VALUE, r;

		minv = Integer.parseInt(sc.next());

		for (int i = 1; i < n; i++) {
			int a = Integer.parseInt(sc.next());
			maxv = Integer.max(maxv, a - minv);
			minv = Integer.min(a, minv);
		}
		System.out.println(maxv);

	}
}
/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