import java.util.Scanner;

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

		long dMax = -1000000001;
		long min = sc.nextLong();
		for (int i = 1; i < n; i++) {
			long r = sc.nextLong();
			dMax = Math.max((r - min), dMax);
			min = Math.min(r, min);
		}
		
		System.out.println(dMax);
		sc.close();
	}
}


/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