C:\test>826456 -N=4000
4000: Took 1.367 seconds

C:\test>826456-a -N=400
400: Took 0.025 seconds

C:\test>826456-a -N=800
800: Took 0.988 seconds

C:\test>826456-a -N=1600
1600: Took 13.999 seconds

C:\test>826456-a -N=3200
3200: Took 119.228 seconds

C:\test>826456-a -N=4000
4000: Took 234.037 seconds