# -*- coding:utf-8 -*-
from itertools import combinations

calc_distance = lambda xs: abs(xs[0] - xs[1])
if __name__ == '__main__':
    n = int(input())
    xn = set(map(int, input().split()))
    if len(xn) < 0:
        print(0)
    else:
        print(min(map(calc_distance, combinations(xn, 2))))