import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int n=Integer.valueOf(sc.next());
		int min=Integer.valueOf(sc.next());
		int dmax=Integer.MIN_VALUE;
		
		for(int i=1;i<n;i++){
			int next=Integer.valueOf(sc.next());
			int d=next-min;
			if(d>dmax)dmax=d;
			if(next<min)min=next;
		}
		System.out.println(dmax);
	}
}
/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