import java.util.*;
public class Main{
	public static void main(String [] args){
		Scanner sc = new Scanner (System.in);
		int n = sc.nextInt(); 
		int Rt [] = new int[n];
        for(int i = 0; i < n; i++) {
			Rt[i] = sc.nextInt();
		}
		int Rmax = Integer.MIN_VALUE;
        int Rmin = Rt[0];
		
		for(int j = 1; j < n; j++) {
			Rmax = Math.max(Rmax, Rt[j] - Rmin);
			Rmin = Math.min(Rmin, Rt[j]);
		}
		System.out.println(Rmax);
	}
}
/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