# Problem 592: Factorial trailing digits 2
For any N, let f(N) be the last twelve hexadecimal digits before the
trailing zeroes in N!. For example, the hexadecimal representation of
20! is 21C3677C82B40000, so f(20) is the digit sequence 21C3677C82B4.
Find f(20!). Give your answer as twelve hexadecimal digits, using
uppercase for the digits A to F.