n = int(input())
xn = list(map(int, input().split(' ')))

sn = sorted(xn)

df = []
mn = 10 ** 6 + 1
for i in range(1, n):
    v = sn[i] - sn[i - 1]
    if v != 0 and mn > v:
        mn = v
if mn == 10 ** 6 + 1:
    print(0)
else:
    print(mn)