n,C=map(int,input().split())
L=50
V=list(map(int,input().split()))
W=list(map(int,input().split()))
q=[[[-1]*(L+1) for j in range(L+1)] for i in range(L+1)]
for i1 in range(n):
  for i2 in range(n):
    v1,w1=V[i1],W[i1]
    v2,w2=V[i2],W[i2]
    if w1+w2<=C and v1!=v2:
      q[C-w1-w2][v1][v2]=v1+v2
ans=0
for c in reversed(range(L+1)):
  for v1 in range(L+1):
    for v2 in range(L+1):
      if q[c][v1][v2]!=-1:
        for i3 in range(n):
          v3,w3=V[i3],W[i3]
          if c-w3>=0 and v1!=v3 and v2!=v3:
            if v1<v2>v3 or v1>v2<v3:
              q[c-w3][v2][v3]=max(q[c-w3][v2][v3],q[c][v1][v2]+v3)
              ans=max(ans,q[c-w3][v2][v3])
print(ans)