How to determing the number of tower?

FHE Questions
1

As the title, how to determine the number of tower? which is the parameter numTower in OpenFHE.

2

Once the crypto context is initialized, encrypt a plaintext to generate a ciphertext, say ctxt. Then you can print out the number of towers in the primary ciphertext coefficient modulus (Q) as follows:

std::vector<double> x = {0.25, 0.75, 2.0, 4.0};
Plaintext ptxt = cryptoContext->MakeCKKSPackedPlaintext(x);
auto ctxt= cryptoContext->Encrypt(keyPair.publicKey, ptxt);
std::cout << "numTowers: " << ctxt->GetElements()[0].GetAllElements().size() << std::endl;

Note that, OpenFHE uses “extra” auxiliary towers - as part of auxiliary RNS modulus P - which are only used in some intermediate computations. The commands above do not show those extra towers.