projecteuler Problem 20

n! means n (n 1) ... 3 2 1

For example, 10! = 10 9 ... 3 2 1 = 3628800,
and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.

Find the sum of the digits in the number 100!

A = reduce(lambda a,b : a*b, range(1,101))
sum = 0
for n in str(A):
    sum+=int(n)
print sum