import sys

sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
# md = 10**9+7
md = 998244353

n, m = LI()
aa = LI()[::-1]
pp = LI()[::-1]
ptoi = {p: i for i, p in enumerate(pp)}

dp = [[] for _ in range(m+1)]
dp[0] = [-1]

for a, p in zip(aa, pp):
    for s in range(m-a, -1, -1):
        if dp[s] == []: continue
        dp[s+a].append(p)

if dp[m] == []:
    print(-1)
else:
    ans = []
    mx = n+5
    s = m
    while s:
        for p in sorted(dp[s]):
            i = ptoi[p]
            if i >= mx: continue
            mx = i
            ans.append(n-ptoi[p])
            s -= aa[i]
            break
    print(len(ans))
    print(*ans)