>time < nul & echo. & perl !.pl > output & time < nul & echo.
The current time is: 14:46:18.10
Enter the new time:
The current time is: 14:46:18.76
Enter the new time:

##</code><code>##

output = (((((((((((((X0*Y0)+(X1*Y1))+((X2*Y2)+(X3*Y3)))+...