import java.util.*;


class Main {

    public static void main(String[] args){

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int a = sc.nextInt();
        int b = sc.nextInt();
        
        int maxProfit = b - a;
        
        int min = Math.min(a,b);  // the minimum number in the dataset 

        while(sc.hasNextInt()){
            int next = sc.nextInt();
            
            maxProfit = Math.max(maxProfit, next - min);
            
            min = Math.min(min, next);
        }


        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