№8 — #8180

from itertools import *
k = 0
for w in product('0123456789AB', repeat=5):
    s = ''.join(w)
    if s[0] != '0' and sum(c in 'AB' for c in s) == 2 and s[1] != s[2] and '00' not in s:
        k += 1
print(k)