import java.util.Scanner;

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

        // 初期値を仮で最小値に
        int minv = scan.nextInt();
        // 更新できるように最大値に十分小さい値を
        int maxv = Integer.MIN_VALUE;

        for(int i=1;i<n;i++){
           int in = scan.nextInt();
           // 最大値の更新
           maxv = Math.max(maxv, in-minv);
           // 最小値の更新
           minv = Math.min(minv, in);
        }
        System.out.println(maxv);
    }
}
/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