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