Factorial Digit Sum

Given a non-negative integer n, compute the sum of the digits of its factorial \(n!\). Recall that the factorial of \(n\) is defined as \(n! = \prod_{i=1}^{n} i\), with the convention that \(0! = 1\). This problem requires you to calculate \(n!\) and then determine the sum of all digits in its decimal representation.

inputFormat

The input consists of a single line containing a non-negative integer n.

outputFormat

Output a single integer representing the sum of the digits of \(n!\).

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