juliusgeo

from functools import reduce as red; from math import \
(factorial as fact, comb);import sys;from decimal import \
      (getcontext as c,Decimal as dc);(a:=range,
       b:=int(sys.                 argv[1]));c\
       ().prec=b;                  ber=lambda\
       e,f=[dc(1)]:                [f.append(
       1-sum(comb(h                ,g)*f[g]/(h
       - g + 1) for                g in a(h)))for
       h in a(1, e                 + 1)] and abs(
      f[-1]);print                 ((2 * fact(b) /