import java.util.*;
public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
      	int n = sc.nextInt();
      	int[] a = new int[n];
      	int max = 0;
      	for(int i=0; i<n; i++){
        	a[i] = sc.nextInt();
        }
      	for(int j=0; j<n; j++){
        	for(int k=0; k<=j; k++){
            	if(Math.abs(a[j]-a[k])>max){
                	max = Math.abs(a[j]-a[k]);
                }
            }
        }
      	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