def main():
    N = int(input())
    X = tuple(map(int, input().split()))

    x = sorted(X)
    l = [0] * (N - 1)
    for i in range(N - 1):
        l[i] = x[i+1] - x[i]

    n = list(filter(lambda i: i > 0, l))
    if not len(n):
        print(0)
    else:
        print(min(n))

main()