#include <bits/stdc++.h>
using namespace std;

using Line = bitset<2001>;

int main()
{
    int N, M;
    cin >> N >> M;
    vector<int> A(N);
    for (int &a : A)
        cin >> a;
    vector<int> P(N);
    for (int &p : P)
        cin >> p;
    vector<int> Pinv(N);
    for (int i = 0; i < N; ++i)
        Pinv[P[i] - 1] = i;
    int last_idx = -1;
    vector<int> ans;
    for (int i = 0; i < N; ++i)
    {

        int p_idx = Pinv[i];
        // cout << p_idx << " " << i << " " << M << " " << A[p_idx] << endl;
        if (p_idx <= last_idx)
            continue;
        Line z = 0; z[0] = 1;
        for (int j = p_idx + 1; j < N; ++j)
            z |= z << A[j];
        // cout << z[1] << " " << z[0] << endl;
        if (M >= A[p_idx] && z[M - A[p_idx]])
        {
            ans.push_back(p_idx + 1);
            last_idx = p_idx;
            M -= A[p_idx];
            i = -1;
        }
    }
    if (M != 0)
    {
        cout << -1 << endl;
        assert(ans.empty());
    }
    else
    {
        assert(!ans.empty());
        cout << ans.size() << endl;
        for (int x : ans)
            cout << x << " ";
        cout << endl;
    }
}