#include <bits/stdc++.h>
using namespace std;
template <class T>
void show(const vector<T> &a) {
  for (T x : a) cout << x << " ";
  cout << '\n';
}
const long long sze = 3e5 + 50, oo = 1e18 + 500, mod = 1e9 + 7;
const long double eps = 1e-9, PI = 2 * acos(0.0);
vector<long long> vertices[sze];
vector<char> visit(sze, false);
vector<char> used(sze, false);
vector<long long> arr(sze, 0);
long long n, m, k;
long long A, B;
long long cnt = 0;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long s;
  cin >> m >> k >> n >> s;
  vector<long long> a(m);
  for (long long i = 0; i < m; i++) {
    cin >> a[i];
  }
  map<long long, long long> etalon;
  for (long long i = 0; i < s; i++) {
    long long val;
    cin >> val;
    etalon[val]++;
  }
  map<long long, long long> temp;
  for (long long i = 0; i < k - 1; i++) {
    if (etalon.find(a[i]) != etalon.end()) {
      temp[a[i]]++;
    }
  }
  long long r = k - 1;
  for (long long l = 0; l + k - 1 < m; l++) {
    long long left = m - n * k - l % k;
    if (r - l + 1 - k > 0) left -= r - l + 1 - k;
    for (long long del = 0; del <= left && r < m; del++, r++) {
      if (etalon.find(a[r]) != etalon.end()) {
        temp[a[r]]++;
      }
      bool flag = (temp.size() == etalon.size());
      for (auto to : temp) {
        if (!flag) break;
        if (etalon[to.first] > to.second) {
          flag = false;
        }
      }
      if (flag) {
        cout << l % k + (r - l + 1) - k << '\n';
        for (long long j = 0; j < l % k; j++) {
          cout << j + 1 << " ";
        }
        map<long long, long long> ans;
        cnt = 0;
        for (long long j = l; cnt < (r - l + 1) - k && j <= r; j++) {
          if (etalon.find(a[j]) != etalon.end() && ans[a[j]] < etalon[a[j]]) {
            ans[a[j]]++;
          } else {
            cout << j + 1 << " ";
            cnt++;
          }
        }
        return 0;
      }
    }
    if (temp.find(a[l]) != temp.end() && temp[a[l]]) temp[a[l]]--;
  }
  cout << "-1";
  return 0;
}
