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

li.sort()
#print li

dist = []
if N <= 1:
    print 0
else:
    for i in xrange(N-1):
        dist.append(li[i+1] - li[i])
        
#print dist

while 0 in dist:
    dist.remove(0)
#print dist
print min(dist)