#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T &x) {
  x = 0;
  char ch = getchar();
  int fh = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') fh = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  x *= fh;
}
template <typename T>
void write(T x) {
  if (x < 0) x = -x, putchar('-');
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
template <typename T>
void writeln(T x) {
  write(x);
  puts("");
}
int m, k, n, s, aim;
int a[500005];
int b[500005];
int limit[500005];
int cnt[500005];
signed main() {
  cin >> m >> k >> n >> s;
  for (int i = 1; i <= m; ++i) cin >> a[i];
  memset(limit, 0x3f, sizeof(limit));
  for (int i = 1; i <= s; ++i) {
    cin >> b[i];
    if (limit[b[i]] > 1000000007)
      limit[b[i]] = 1, aim++;
    else
      limit[b[i]]++;
  }
  int l = 1, r = 1, cur = 0;
  while (1) {
    cnt[a[r]]++;
    if (cnt[a[r]] == limit[a[r]]) cur++;
    if (cur == aim) break;
    r++;
    if (r > m) {
      cout << -1 << endl;
      return 0;
    }
  }
  while (1) {
    int lenl = l - 1, lenr = m - r;
    int rem = r - l + 1 + lenl % k + lenr % k;
    int tot = (rem >= k ? lenl / k + lenr / k + 1 : lenl / k + lenr / k);
    if (tot >= n) {
      cout << m - tot * k << endl;
      if (r - l + 1 >= k) {
        vector<int> vec;
        for (int i = l; i <= r; ++i)
          if (limit[a[i]] > 1000000007) {
            vec.push_back(i);
          } else {
            if (limit[a[i]] == 0)
              vec.push_back(i);
            else
              limit[a[i]]--;
          }
        for (int i = (lenl / k) * k + 1; i < l; ++i) cout << i << ' ';
        for (int i = 0; i < r - l + 1 - k; ++i) cout << vec[i] << ' ';
        for (int i = 1; i <= lenr % k; ++i)
          cout << m - (lenr / k) * k - i + 1 << ' ';
        cout << endl;
      } else if (lenr % k + r - l + 1 >= k) {
        for (int i = (lenl / k) * k + 1; i < l; ++i) cout << i << ' ';
        for (int i = 1; i <= m - tot * k - (l - ((lenl / k) * k + 1)); ++i)
          cout << m - (lenr / k) * k - i + 1 << ' ';
        cout << endl;
      } else {
        for (int i = 1; i <= lenr % k; ++i)
          cout << m - (lenr / k) * k - i + 1 << ' ';
        for (int i = 1; i <= m - tot * k - lenr % k; ++i)
          cout << (lenl / k) * k + i << ' ';
        cout << endl;
      }
      return 0;
    }
    cnt[a[l]]--;
    if (cnt[a[l]] == limit[a[l]] - 1) cur--;
    l++;
    while (cur != aim) {
      r++;
      if (r > m) {
        cout << -1 << endl;
        return 0;
      }
      cnt[a[r]]++;
      if (cnt[a[r]] == limit[a[r]]) cur++;
      if (cur == aim) break;
    }
  }
  return 0;
}
