Multiplying two 64-bit numbers gives a 128-bit result. 

(a) Assuming the inputs and outputs are terminated by flip-flops, how many combinations of start and end flip-flops exist in the system?

(b) It takes 30 s to check for a violation on a register–register path by hand. If you wanted to check for setup and hold violations on each of these paths in nine different processes, estimate the time it would take to perform a complete timing analysis on the multiplier.