import java.util.*;
class B{
	static Scanner s = new Scanner(System.in);
	public static void main(String[] args) {
		TreeSet<Integer> b = new TreeSet<Integer>();
		for(int i=Integer.parseInt(s.next());i>0;--i) {
			b.add(Integer.parseInt(s.next()));
		}
		Integer[] in = b.toArray(new Integer[0]);

		int r=Integer.MAX_VALUE;
		for(int i=0;i<in.length-1;++i) {
			r=Math.min(r, Math.abs(in[i]-in[i+1]));
		}
		System.out.println((r==Integer.MAX_VALUE)?0:r);
	}
}