Fixed deprecated imports. Now works with pypy3. Added pypy3 to README

README.md

@@ -6,12 +6,16 @@ To solve all puzzles with implemented solutions run
 ```console
 $ python3 main.py 
 ```
-or alternatively make the main program executable
+or alternatively make the main program executable.
 ```console
 $ chmod +x main.py
 $ ./main.py
 ```
-For other options see `./main.py -h`
+For faster execution use `pypy3`.
+```console
+$ pypy3 main.py
+```
+For other options see `./main.py -h`.
 ```console
 $ ./main.py -h
 usage: main.py [-h] [-d DAY[-DAY]] [-i INPUT] [-t]

day10.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
-from fractions import gcd, Fraction
+from math import gcd
+from fractions import Fraction
 from itertools import product
 from functools import total_ordering
 from collections import defaultdict

day12.py

@@ -1,12 +1,9 @@
 #!/usr/bin/env python3
 
 from itertools import combinations
-from fractions import gcd
+from math import lcm
 from functools import reduce
 
-def lcm(a, b):
-    return (a * b) / gcd(a, b)
-
 def comp(a, b):
     def f(arg):
         x, y = arg