import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {

	public static final int MAX = 200000;

	public static void main(String[] args) throws IOException {

		int Nums[] = new int[MAX];

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String n = br.readLine();

		for(int i=0; i<Integer.parseInt(n); i++){
			 Nums[i] = Integer.parseInt(br.readLine());
			}


		int max = -2000000000;
		int min = Nums[0];

		for(int i=1; i<Integer.parseInt(n); i++){
			max = Math.max(max, Nums[i]-min);
			min = Math.min(min, Nums[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