a=int(input())
b=[int(i) for i in input().split()]

c=set(b)
d=[]
for i in c:
    d.append(i)
d.sort()
e=[]
for i in range(1,len(d)):
    e.append(d[i]-d[i-1])

if e==[]:
    print(0)
else:
    print(min(e))