№8 — #816

from itertools import product
count = 0
for digits in product(range(12), repeat=5):
    if digits[0] == 0:
        continue
    if digits.count(7) == 1:
        gt8 = sum(1 for d in digits if d > 8)
        if gt8 <= 3:
            count += 1
print(count)