N = input()
li = map(int, raw_input().split())
li.sort()

dist = []
if N <= 1:
    print 0
else:
    for i in xrange(N-1):
        dist.append(li[i+1] - li[i])
    dist = filter(lambda x: x>0, dist)  #0を除去
    if dist == []:  #0しかなかったら
        print 0
    else:   #0以外の距離があれば
        print min(dist)