import java.util.Scanner;

class Main{

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        int n = Integer.parseInt(scan.nextLine());
        int dif = -2000000000;
        int min = Integer.parseInt(scan.nextLine());
        int number;
        for(int i=1; i<n; i++){
            number = Integer.parseInt(scan.nextLine());
            dif = Math.max(dif, number-min);
            min = Math.min(min, number);
        }
        
        System.out.println(dif);
    }
    
}
/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