n = int(raw_input())
l = map(int, raw_input().split())
l.sort()
if len(l) == 1:
    print 0
else:
    mn = 10**7
    for i in range(n-1):
        d = l[i+1] - l[i]
        if d > 0:
            mn = min(mn,d)
    print mn