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

public class Main {
	
	private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		int n = Integer.parseInt(br.readLine());
		
		int maxv = Integer.MIN_VALUE;
		int min = Integer.MAX_VALUE;
		
		for(int i = 0; i < n; i++){
			int r = Integer.parseInt(br.readLine());
			maxv = Math.max(maxv, r - min);
			min = Math.min(min, r);
		}
		
		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