def Eratosthenes(n):
    isPrime = [True]*(n+1)
    isPrime[0], isPrime[1] = False, False
    for i in range(2, n+1):
        if isPrime[i]:
            for j in range(i*i, n+1, i):
                isPrime[j] = False
    return isPrime

def fast_zeta(F):
    isPrime = Eratosthenes(len(F))
    for i in range(2, len(F)):
        if isPrime[i]:
            for j in range((len(F)-1)//i, 0, -1):
                F[j] += F[j*i]

def fast_mobius(F):
    isPrime = Eratosthenes(len(F))
    for i in range(2, len(F)):
        if isPrime[i]:
            for j in range(1, (len(F)-1)//i+1):
                F[j] -= F[j*i]

N, W = map(int, input().split())
X = list(map(int, input().split()))
Y = list(map(int, input().split()))

S = [0]*(10**5*2+1)
for i in range(N):
    S[X[i]] += Y[i]

fast_zeta(S)
print(max(S[W:]))