import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner scan=new Scanner(System.in);
        int N=scan.nextInt();
        int[] A=new int[N];
        int i;
        int answer=0;
        for(i=0;i<N;i++){
            A[i]=scan.nextInt();
            for(int j=0;j<i;j++){
                if(answer<Math.abs(A[i]-A[j])){
                    answer=Math.abs(A[i]-A[j]);
                }
            }
        }
        System.out.println(answer);
    }
}
/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