import java.util.Scanner;

public class Main {
	
	static Scanner scan;
	
	public static void main(String[] main) {
		scan = new Scanner(System.in);
		
		// Get the input number of array's elements.
		final int n = scan.nextInt();
		
		// Get the input array.
		int list[] = new int[n];
		for(int i = 0; i < n; i++) {
			list[i] = scan.nextInt();
		}
		
		// Calculate the max profit.
		int max = list[1] - list[0];
		int key = list[0];
		for(int i = 0; i < n-1; i++) {
			for(int j = i+1; j < n; j++) {
				if(key < list[i]) break;
				if(max < list[j] - list[i]) {
					max = list[j] - list[i];
					key = list[i];
				}
			}
		}

		// Output the result.
		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