void kaprekarNumbers(int p, int q) {
    bool found = false;

    for (int i = p; i <= q; i++) {
        long long sq = 1LL * i * i;
        string num_str = to_string(sq);

        int len = num_str.length();
        int mid = len / 2;

        long long left = (mid == 0) ? 0 : stoll(num_str.substr(0, mid));
        long long right = stoll(num_str.substr(mid));

        if (left + right == i) {
            found = true;
            cout << i << " ";
        }
    }

    if (!found) cout << "INVALID RANGE";
}