Factorial Computation

Given a non-negative integer \( n \), compute its factorial defined as:

\( n! = n \times (n-1) \times \cdots \times 1 \) for \( n > 0 \) and \( 0! = 1 \).

Your task is to read an integer from standard input, calculate its factorial and print the result to standard output.

inputFormat

The input consists of a single non-negative integer ( n ) provided via standard input.

outputFormat

Output the factorial of the integer ( n ) to standard output.## sample

0

1