e20

memo = dict()
memo[1] = 1

def factorial(n):
    if n in memo:
        return n
    else:
        val = n * factorial(n - 1)
        memo[n] = val
        return val

# print(factorial(1))
# print(factorial(2))
# f100 = factorial(100)
# print(f100)
# tokens = list(str(f100))
# print(tokens)
# print(sum([int(x) for x in tokens]))
print(sum([int(x) for x in list(str(factorial(100)))]))