Add compiling with Cython in Python solution#72

Simple compiling with Cython gets about 50% performance improvement in my Arch Linux box. Environment: ``` $ uname -a Linux zbox 4.19.11-arch1-1-ARCH #1 SMP PREEMPT Thu Dec 20 03:40:28 UTC 2018 x86_64 GNU/Linux $ python --version Python 3.7.1 $ cython --version Cython version 0.29.2 $ gcc --version | head -1 gcc (GCC) 8.2.1 20181127 $ cat /proc/cpuinfo | grep "model name" model name : Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz model name : Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz model name : Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz model name : Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz $ cat /proc/meminfo | grep MemTotal MemTotal: 8142204 kB ``` Testing: ``` $ time python main.py 331665 real 0m15.492s user 0m15.451s sys 0m0.014s ``` ``` $ time ./main 331665 real 0m8.080s user 0m8.063s sys 0m0.007s ```