import java.util.Scanner;

public class Main {
	public static void main(String args[]){
		int n,min=0,a,p=0;
		Scanner sc=new Scanner(System.in);
		n=sc.nextInt();
		for (int i=0;i<n;i++){
			a=sc.nextInt();
			if (i>=2){
				if (a-min>p){p=a-min;}
				if (a<min){min=a;}
			}else if (i==0){
				min=a;
			}else if (i==1){
				p=a-min;
				if (a<min){min=a;}
			}
		}
		System.out.println(p);
	}
}
/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