import java.util.Scanner;

import java.io.*;
public class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(reader.readLine());
        String[] s = reader.readLine().split(" ");
        int[] arr = new int[n];
        for(int i=0;i<n;i++){
            arr[i]=Integer.parseInt(s[i]);
        }
        int min=Integer.MAX_VALUE;
        int ans=0;
        //主要逻辑:
        for(int i=0;i<n;i++){
            if(arr[i]<min){
                min=arr[i];
                continue;
            }
            if(arr[i]>min){
                ans=Math.max(ans,arr[i]-min);
            }
        }
        System.out.print(ans);
    }
}