import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] a = new int[n]; 
        for(int a_i=0; a_i < n; a_i++){
            a[a_i] = in.nextInt();
        }
        // your code goes here
        int x =0, result,re = 0, ans = 0 ;
        while(x < n-1){
            for(int i = x+1; i < n;i++){
                result = a[x]-a[i];
                if(result < 0){
                 result = result*-1;   
                }
                if(re > result){
                    ans = result;
                }
                 re = result; 
            }
            x++;
        }
        System.out.println(ans);
    }
}