import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.next());
		int[] R = new int[n];
		
		for(int i=0;i<n;i++){
			R[i] = Integer.parseInt(sc.next());
		}
		
		int max=R[1]-R[0];
		int Rmin=R[0];
		for(int i=1;i<n;i++){
			if(max<R[i]-Rmin) max=R[i]-Rmin;
			if(Rmin>R[i]) Rmin=R[i];
		}
		System.out.println(max);

	}

}
/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