N,K = list(map(int,input().split()))
A = list(map(int,input().split()))
A.sort(reverse=True)

ans = 0
for i in range(1<<(N-1)):
    now = K
    for j in range(N-1):
        if((i>>j)&1 == 0):continue
        now %= A[j]
    now %= A[-1]
    ans = max(ans,now)
print(ans)