import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		int j,k;
		int maxv = -1000000000;
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.nextLine());
		int R[] = new int[n];
		for(j=0;j<n;j++)R[j] = Integer.parseInt(sc.next());
		int minv = R[0];

			for(k=1;k<n;k++){
				maxv = Math.max(R[k]-minv,maxv);
				minv = Math.min(minv,R[k]);
				}
			System.out.println(maxv);
	}

}
/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