Gifting home to kids and paying them rent

If I gift my home to my two children, I understand that I'll need to pay them full-market rent to continue to live there. If they both also continue to live there with me, though, is the rent reduced pro-rata, please - ie I'd need to pay them one third of the market rent with both of them still there, or half / two thirds (?), if only one continues to live there with me? Thank you.

Hi,
The rent would be at the going rate no matter who remained in the house.
Thank you.