#include <bits/stdc++.h>
using namespace std;
int n, k, m, s;
int a[500005], b[500005], c[500005], r;
int main() {
  ios_base::sync_with_stdio(false);
  cin >> m >> k >> n >> s;
  int len = k + m - n * k;
  for (int i = 0; i < m; ++i) cin >> a[i];
  for (int i = 0; i < s; ++i) {
    int x;
    cin >> x;
    if (b[x] == 0) r++;
    b[x]++;
  }
  for (int i = 0; i < len; ++i) {
    c[a[i]]++;
    if (c[a[i]] == b[a[i]] and b[a[i]] > 0) r--;
  }
  int i = 0, j = len;
  for (; j <= m; ++i, ++j) {
    if (r == 0 and i % k == 0) break;
    c[a[i]]--;
    if (c[a[i]] == b[a[i]] - 1 and b[a[i]] > 0) r++;
    c[a[j]]++;
    if (c[a[j]] == b[a[j]] and b[a[j]] > 0) r--;
  }
  if (r != 0 or i % k != 0)
    cout << -1 << endl;
  else {
    cout << len - k << endl;
    int cnt = len - k;
    for (int q = i; q < j, cnt; ++q) {
      if (b[a[q]] == 0) {
        cout << q + 1 << " ";
        cnt--;
      } else
        b[a[q]]--;
    }
  }
  return 0;
}
