#include <bits/stdc++.h>
using namespace std;
int read() {
  int f = 1;
  int res = 0;
  char ch;
  do {
    ch = getchar();
    if (ch == '-') f = -f;
  } while (ch < '0' || ch > '9');
  do {
    res = res * 10 + ch - '0';
    ch = getchar();
  } while (ch >= '0' && ch <= '9');
  return f == 1 ? res : -res;
}
void fast_io() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
const int N = 1000010;
const int mod = 998244353;
const long long INF = 1e18;
int n, m, q;
int A[N], B[N], mx[N];
int head[N], to[N * 2], nxt[N * 2], tot;
void addEdge(int u, int v) {
  tot++;
  nxt[tot] = head[u];
  to[tot] = v;
  head[u] = tot;
}
long long mmax(long long a, long long b) { return a > b ? a : b; }
long long mmin(long long a, long long b) { return a < b ? a : b; }
pair<long long, long long> proc[N];
int main() {
  fast_io();
  int k, s;
  cin >> m >> k >> n >> s;
  int res = m;
  int ls = 0, rs = m;
  for (int i = 0; i < m; i++) cin >> A[i];
  unordered_map<int, int> target;
  for (int i = 0; i < s; i++) {
    int tmp;
    cin >> tmp;
    target[tmp]++;
  }
  int sz = target.size();
  int l, r;
  l = -1;
  unordered_map<int, int> cur;
  int cnt = 0;
  for (r = 0; r < m; r++)
    if (target.count(A[r])) {
      cur[A[r]]++;
      if (cur[A[r]] == target[A[r]]) cnt++;
      while (cnt == sz) {
        if (r - l - k + (l + 1) % k < res) {
          res = r - l - k + (l + 1) % k;
          ls = l;
          rs = r;
        }
        l++;
        if (target.count(A[l])) {
          if (cur[A[l]] == target[A[l]]) cnt--;
          cur[A[l]]--;
        }
      }
    }
  if (res + n * k > m)
    cout << -1 << endl;
  else if (res <= 0) {
    cout << 0 << endl;
  } else {
    cout << res << endl;
    cur.clear();
    int l = ls + 1;
    int r = rs;
    vector<int> del;
    int i = 0;
    while (rs - ls - k + del.size() < res) {
      del.push_back(i);
      i++;
    }
    for (l = ls + 1; l <= r; l++)
      if (target.count(A[l])) {
        cur[A[l]]++;
        if (del.size() < res && cur[A[l]] > target[A[l]]) del.push_back(l);
      }
    for (l = ls + 1; l <= r && del.size() < res; l++)
      if (!target.count(A[l])) {
        del.push_back(l);
      }
    for (int i = 0; i < del.size(); i++) {
      cout << del[i] + 1 << " ";
    }
    cout << endl;
  };
  return 0;
}
