n = int(input())
x = list(map(int,input().split()))
x.sort()
mi = 10 ** 6
f = False
for i in range(len(x) - 1):
    s = x[i + 1] - x[i]
    if mi > s and s > 0:
        f = True
        mi = s
if n == 1 or f == False:
    print(0)
else:
    print(mi)