import java.util.Scanner;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int n = Integer.parseInt(sc.next());

        int r0 = Integer.parseInt(sc.next());
        int r1 = Integer.parseInt(sc.next());

        int max = r1-r0;
        int min = Math.min(r0,r1);

        for(int i = 2; i < n; i++){
            int r = Integer.parseInt(sc.next());
            max = Math.max(max, r - min);
            min = Math.min(min,r);
        }
        
        System.out.println(max);
    }
}

/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