import sys
input = sys.stdin.readline

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

# エラトステネスの篩を用いた素因数分解・約数列挙
MAX=5*10**5+10 # 使いたい最大値を指定

# 線形篩。エラトステネスの篩を線形にできる。
Sieve=[-1]*MAX
Primes=[]

for i in range(2,MAX):
    if Sieve[i]==-1:
        Primes.append(i)
        Sieve[i]=i

    for p in Primes:
        if p*i>=MAX or p>Sieve[i]:
            break
        else:
            Sieve[p*i]=p


# 素因数分解
def fact(x):
    D=dict()
    while x!=1:
        k=Sieve[x]
        if k in D:
            D[k]+=1
        else:
            D[k]=1
        x//=k
    return D

# 約数列挙
def faclist(x):
    LIST=[1]
    while x!=1:
        k=Sieve[x]
        count=0
        while x%k==0:
            count+=1
            x//=k

        LIST2=[]
        for l in LIST:
            for i in range(1,count+1):
                LIST2.append(l*k**i)
        LIST+=LIST2

    return LIST

LIST=[[] for i in range(200001)]

for i in range(N):
    for k in faclist(X[i]):
        LIST[k].append(Y[i])

OK=[0]*200001
LANS=0

for i in range(W,200001):
    if OK[i]==1:
        continue

    w=i
    for j in range(w,200001,w):
        OK[j]=1

    ANS=0

    for c in LIST[w]:
        ANS+=c

    LANS=max(LANS,ANS)

print(LANS)