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 factorial = 1;
        for (int i = n; i > 1; i--) {
            factorial *= i;
        }
        int[] differences = new int[(factorial/(2*(n-2)))];
        
        // store differences
        int d = 0;
        for (int i = 0; i < a.length; i++) {
            for (int j = i+1; j < a.length; j++) {
                differences[d] = Math.abs(a[i] - a[j]);
                d++;
            }
        }
        
        // minimum
        int minimum = 0;
        for (int i = 0; i < differences.length; i++) {
            if (i == 0) {
                minimum = differences[i];
            } else if (differences[i] < minimum) {
                minimum = differences[i];
            }
        }
        System.out.println(minimum);
    }
}