class SegmentTree:
    def __init__(self, init_val, segfunc, ide_ele):
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        self.size = n
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        k += self.num
        self.tree[k] = x
        while k > 1:
            k >>= 1
            self.tree[k] = self.segfunc(self.tree[2*k], self.tree[2*k+1])

    def query(self, l, r):
        if r==self.size:
            r = self.num

        res = self.ide_ele

        l += self.num
        r += self.num
        right = []
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                right.append(self.tree[r-1])
            l >>= 1
            r >>= 1

        for e in right[::-1]:
            res = self.segfunc(res,e)
        return res

    def bisect(self,l,r,x):
        if r==self.size:
            r = self.num
        l += self.num
        r += self.num
        segment = []
        segment_r = []
        while l<r:
            if l&1:
                segment.append(l)
                l += 1
            if r&1:
                segment_r.append(r-1)
            l >>= 1
            r >>= 1
        segment += segment_r[::-1]
        tmp = self.ide_ele
        for pos in segment:
            check = self.segfunc(tmp,self.tree[pos])
            if check > x:
                break
            else:
                tmp = check
        else:
            return -1
        
        while pos < self.num:
            check = self.segfunc(tmp,self.tree[2*pos])
            if check > x:
                pos = 2 * pos
            else:
                tmp = check
                pos = 2 * pos + 1
        return pos - self.num

import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import log,gcd

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

N,M = mi()
A = li()
P = li()

pos = [-1] * (N+1)
for i in range(N):
    pos[P[i]] = i

dp = [[False for j in range(M+1)] for i in range(N+1)]
dp[N][0] = True
for i in range(N)[::-1]:
    for j in range(M+1):
        if A[i] <= j:
            dp[i][j] = dp[i+1][j]|dp[i+1][j-A[i]]
        else:
            dp[i][j] = dp[i+1][j]


if not dp[0][M]:
    exit(print(-1))

res = []
L = 0
S = 0
use = [False] * (N+1)
while True:
    for i in range(1,N+1):
        tmp_L = max(L,pos[i]+1)
        tmp_rest = M - S - A[pos[i]]
        if 0 <= tmp_rest and not use[i] and L <= pos[i] and dp[tmp_L][tmp_rest]:
            res.append(i)
            L = max(L,pos[i]+1)
            S = S + A[pos[i]]
            use[i] = True
            break
        else:
            pass
    else:
        break

print(len(res))
print(*[pos[i]+1 for i in res])