import java.util.Scanner;

/**
 * Created by shoya on 2017/04/14.
 */
public class Main {
    public static void main(String... args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        final long INF = 1L << 60;
        long currentmin = INF;
        long maxpro = -INF;
        for (int i = 0; i < n; i++){
            long a = sc.nextInt();
            if (maxpro < a - currentmin)
                maxpro = a - currentmin;
            if (currentmin > a)
                currentmin = a;
        }
        System.out.println(maxpro);
        return;
    }
}
/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