import itertools

N, K = map(int, input().split())
A = sorted(list(map(int, input().split())), reverse=True)
minA = A[-1]

ans = 0
for t in itertools.product((0, 1), repeat=N - 1):
    X = itertools.compress(A[:-1], t)
    k = K
    for x in X:
        k %= x
    k %= minA
    ans = max(ans, k)
print(ans)