n = int(input())
x = list(map(int, input().split()))
x.sort()
ans = 10 ** 9
before = x[0]
for num in x[1:]:
    d = num - before
    if d == 0:
        continue
    ans = min(ans, d)
    before = num
if ans == 10 ** 9:
    print(0)
else:
    print(ans)