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();
        }
        
        Arrays.sort(a);
        
        int minAbs = 1000000007;
        for (int i = 1; i < n-1; i++)
        {
            int temp = Math.abs(Math.min(a[i] - a[i-1], a[i] - a[i+1]));
            if (temp < minAbs)
                minAbs = temp;
            if (minAbs == 0)
                break;
        }
System.out.println(minAbs);
        // your code goes here
    }
}