input()
dat = list(map(int, input().split()))
dat.sort()
ary =[]
for i in range(len(dat)-1):
 ary += [dat[i+1] - dat[i]]
while(min(ary) == 0):
    del(ary[ary.index(min(ary))])
    if(ary == []):
        ary+=[0]
    break
print(min(ary))