Adding auto-generation of dummy input and benchmarks

Here are the benchbark numbers as of first version:
hellwigs for n = 10 took 12
hellwigs for n = 11 took 3
hellwigs for n = 12 took 1
hellwigs for n = 13 took 3
hellwigs for n = 14 took 6
hellwigs for n = 15 took 14
hellwigs for n = 16 took 30
hellwigs for n = 17 took 79
hellwigs for n = 18 took 168
hellwigs for n = 19 took 371
hellwigs for n = 20 took 799
hellwigs for n = 21 took 1696
hellwigs for n = 22 took 3584
hellwigs for n = 23 took 7743
hellwigs for n = 24 took 16427
hellwigs for n = 25 took 56823
(..I stopped waiting for n = 26 :)