n, w = map(int,input().split())
x = list(map(int,input().split()))
y = list(map(int,input().split()))

def GCD(a, b):
    while b != 0:
        tmp = b
        b = a % b
        a = tmp
    return a

rng = max(x) - w
if rng < 0:
    print(0)
    exit(0)

stack = set()
stack.add((0,0))
for i in range(n):
	if x[i] < w:
	    continue
	tmp = set()
	for elm in stack:
		gcd = GCD(elm[0], x[i])
		if gcd >= w:
			tmp.add((gcd,elm[1]+y[i]))
	stack.add((x[i],y[i]))
	stack|=tmp
      
print(max(stack, key=lambda x: x[1])[1])