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

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		if(N == 1) System.out.println("0");
		int[] x = new int[N];
		for(int i = 0; i < N; i++) {
			x[i] = sc.nextInt();
		}
		int MIN = Integer.MAX_VALUE;
		for(int i = 0; i < N; i++) {
			for(int j = i + 1; j < N; j++) {
				if(x[i] == x[j]) continue;
				MIN = Math.min(MIN, (int)Math.abs(x[i] - x[j]));
			}
		}
		if(MIN == Integer.MAX_VALUE) MIN = 0;
		System.out.println(MIN);
	}
}