#include <bits/stdc++.h>
template <class C, class E>
inline bool contains(const C& container, const E& element) {
  return container.find(element) != container.end();
}
template <class T>
inline void checkmin(T& a, T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkmax(T& a, T b) {
  if (b > a) a = b;
}
using namespace std;
int Dec(map<int, int>& m, int k) {
  m[k]--;
  int res = m[k];
  if (res == 0) m.erase(k);
  return res;
}
int n, m, k, s;
set<int> typeIsPending;
map<int, int> typeCount;
map<int, int> seq;
int bestVal;
pair<int, int> bestPos;
int bestRemFirst;
void Check(pair<int, int> p) {
  int seqSize = p.second - p.first + 1;
  int tot = p.first / k + ((m - 1) - p.second) / k + 1;
  if (tot >= n) {
    int remT = p.first % k + seqSize - k;
    if (remT < bestVal) {
      bestVal = remT;
      bestRemFirst = p.first % k;
      bestPos = p;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cout << std::setprecision(15);
  cout << std::fixed;
  cin >> m >> k >> n >> s;
  vector<int> li(m);
  for (int i = (0), _b = ((m)-1); i <= _b; i++) cin >> li[i];
  for (int i = (0), _b = ((s)-1); i <= _b; i++) {
    int f;
    cin >> f;
    seq[f]++;
    typeIsPending.insert(f);
  }
  bestVal = m;
  int lV = 0;
  int rV = -1;
  for (int lV = (0), _b = ((m)-1); lV <= _b; lV++) {
    int seqSize = rV - lV + 1;
    while ((seqSize < k || typeIsPending.size() != 0) && rV < m - 1) {
      rV++;
      seqSize = rV - lV + 1;
      int tType = li[rV];
      typeCount[tType]++;
      if (contains(typeIsPending, tType) && typeCount[tType] == seq[tType])
        typeIsPending.erase(tType);
    }
    if (typeIsPending.size() == 0 && seqSize >= k)
      Check(pair<int, int>(lV, rV));
    int tType = li[lV];
    int v = Dec(typeCount, tType);
    auto it = seq.find(tType);
    if (it != seq.end()) {
      if (v == it->second - 1) typeIsPending.insert(tType);
    }
  }
  if (bestVal == m) {
    cout << -1;
  } else {
    int seqSize = bestPos.second - bestPos.first + 1;
    cout << seqSize - k + bestRemFirst << endl;
    for (int i = (0), _b = ((bestRemFirst)-1); i <= _b; i++) {
      cout << i + 1 << " ";
    }
    int extraNeeded = seqSize - k;
    for (int i = (0), _b = ((seqSize)-1); i <= _b; i++) {
      int pos = bestPos.first + i;
      int t = li[pos];
      auto it = seq.find(t);
      if (it != seq.end())
        Dec(seq, t);
      else {
        if (extraNeeded > 0) {
          cout << pos + 1 << " ";
          extraNeeded--;
        }
      }
    }
  }
  return 0;
}
