import sys

def solve():
    input_data = sys.stdin.read().split()
    if not input_data:
        return
    
    N = int(input_data[0])
    W = int(input_data[1])
    
    X = [int(x) for x in input_data[2:N+2]]
    Y = [int(y) for y in input_data[N+2:2*N+2]]
    
    if not X:
        print(0)
        return
        
    max_x = max(X)
    if W > max_x:
        print(0)
        return
        
    val_sum = [0] * (max_x + 1)
    for i in range(N):
        val_sum[X[i]] += Y[i]
        
    ans = 0
    for g in range(W, max_x + 1):
        curr = 0
        for j in range(g, max_x + 1, g):
            curr += val_sum[j]
        if curr > ans:
            ans = curr
            
    print(ans)

if __name__ == '__main__':
    solve()