import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        int iniNum, RiNum;
        iniNum = scan.nextInt();
        int buyPrice=1000000001, maxProfit=-1000000001;
        
        for(int i=0; i<iniNum; i++){
            RiNum = scan.nextInt();

            maxProfit= i==0? -1000000000: Math.max(maxProfit,RiNum-buyPrice);
            buyPrice=Math.min(buyPrice,RiNum);

        }
        System.out.println(maxProfit);            
    }
}

/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