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];
        int diff=100,d;
        for(int a_i=0; a_i < n; a_i++){
            a[a_i] = in.nextInt();
        }
        for(int a_i=1;a_i<n-1;a_i++)
            for(int j=1;j<n;j++)
            {
            d=a[a_i]-a[j];
            if(d<diff)
                diff=d;
        }
        // your code goes here
        System.out.println(diff);
    }
}