n = int(input())
x = list(map(int, input().split()))

if n == 1:
    print(0)
else:
    ans = 10 ** 18
    for i in range(n - 1):
        for j in range(i + 1, n):
            if x[i] == x[j]: continue
            ans = min(ans, abs(x[i] - x[j]))
    print(ans)