import sys
input = lambda : sys.stdin.readline().rstrip()

sys.setrecursionlimit(2*10**5+10)
write = lambda x: sys.stdout.write(x+"\n")
debug = lambda x: sys.stderr.write(x+"\n")
writef = lambda x: print("{:.12f}".format(x))

# list 多重リスト生成
def dlist(*l, fill=None):
    if len(l)==1:
        return [fill]*l[0]
    ll = l[1:]
    return [dlist(*ll, fill=fill) for _ in range(l[0])]
n,c = list(map(int, input().split()))
l = list(map(int, input().split()))
w = list(map(int, input().split()))
dp = {(-1,-1,0): 0}
ans = 0
while dp:
    ndp = {}
    for (i,j,k),val in dp.items():
        for ii in range(n):
            ll = l[ii]
            ww = w[ii]
            if ll==i or ll==j or ww+k>c:
                continue
            if i!=-1 and j!=-1:
                if (j-i)*(ll-j)>0:
                    continue
                ans = max(ans, val+ll)
            nk = (j,ll,ww+k)
            ndp.setdefault(nk, 0)
            ndp[nk] = max(ndp[nk], val+ll)
    dp = ndp
#     print(dp)
print(ans)