import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[]  arr = new int[n];
        for(int i = 0;i < n;i++){
            arr[i] = sc.nextInt();
        }
        int res = Integer.MIN_VALUE;
        for(int i = 1;i < n;i++){
            int temp = Math.abs(arr[i] - arr[i - 1]);
            res = Math.max(res,temp);
        }
        System.out.println(res);
    }
}