In the C standard library there is a random integer generator that produces 32-bit random integers. This function creates a 64-bit random integer by generating two 32-bit integers and then appending one to the other. Simple but effective.
For anyone interested the pseudo-random number generator in the C library is rather primitive. It deserves to be replaced by something more technologically advanced. For the present time we will continue using the generator in the C standard library.
This program was last tested on 2023-01-18. The outcome was successful.