import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner std = new Scanner(System.in);
		int n = Integer.parseInt(std.next());
		int minval = Integer.parseInt(std.next());;
		int maxpro = (int)-1e+9;
		int nextval = 0;
		for (int i=1; i<n; i++){
			nextval = Integer.parseInt(std.next());
			if(maxpro<(nextval-minval)){maxpro = nextval - minval;}
			if(nextval<minval){minval = nextval;}
		}
		System.out.println(maxpro);
	}
}
/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