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();
        TreeMap<Integer, Integer> nums = new TreeMap<Integer, Integer>();
        boolean done = false;
        for(int a_i=0; a_i < n; a_i++){
            int nextVal = in.nextInt();
            if(nums.containsKey(nextVal)) {
                System.out.println(0);
                done = true;
                break;
            }
            nums.put(nextVal, 0);
        }
        
        if(!done) {
            Set<Integer> keyset = nums.keySet();
            Integer[] keys = keyset.toArray(new Integer[0]);
            int minDiff = keys[1] - keys[0];
            //minDiff = minDiff < 0 ? -minDiff : minDiff;

            for(int i = 2; i < keys.length; i++) {
                int diff = keys[i] - keys[i - 1];
                //diff = diff < 0 ? -diff : diff;
                if(diff < minDiff)
                    minDiff = diff;
                if(minDiff == 0)
                    break;
            }
            System.out.println(minDiff);
        }
            
    }
}