A private network uses a NAPT device at public IP address $192\mathrm{.}172\mathrm{.}56\mathrm{.}40$ The computers in the network use addresses of the form $10\mathrm{.}0\mathrm{.}0.$x$/22.$ Suppose that computer inside the NATed network sends a request with

Source address: $10\mathrm{.}0\mathrm{.}1\mathrm{.}20$

Source port: $446$

Destination address: $138\mathrm{.}123\mathrm{.}45\mathrm{.}40$

Destination port: $80$

The next available port number on the NAPT device is $14400.$