import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int minR=sc.nextInt();
		int maxR=-1000000000;
		for(int i=1;i<n;i++){
			int R=sc.nextInt();
			maxR=Math.max(maxR,R-minR);
			minR=Math.min(minR, R);
		}
		System.out.println(maxR);
	}

}
/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