import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] a) {
		Scanner s = new Scanner(System.in);
		int N=s.nextInt(),i=0,d,m=Integer.MAX_VALUE;
		int[] X=new int[N];
		for(;i<N;)X[i++]=s.nextInt();
		Arrays.sort(X);
		for(i=0;i<N-1;){
			d=Math.abs(X[i]-X[++i]);
			m=(d>0&&d<m)?d:m;
		}
		System.out.println(m==Integer.MAX_VALUE?0:m);
	}
}