def comb(n,k):
if k > n: return 0
if n < mod:
return (((int(fact[n]) * int(ifact[k])) % mod )* int(ifact[n-k])) % mod
n_digits, k_digits = pe.base_repr(n, mod), pe.base_repr(k, mod)
res = 1
for top, bot in zip(n_digits, k_digits):
res = (res * C(top, bot)) % mod
return res
def F_new(g):
k = 2
d = pe.base_repr(g, 2)
while True:
k = fast_forward(d, k) % mod
if not sum(d):
return (k - 2) % mod
else:
k += 1
base_dec(d, k)
