The factorial of the integer $n$, written $n!$, is defined as:

$n!=n\times(n-1)\times(n-2)\times\text{}\cdots\times3\times2\times1$

Calculate and print the factorial of a given integer.

For example, if $n=30$, we calculate $30\times29\times28\times\text{...}\times2\times1$ and get $265252859812191058636308480000000$.

Function Description

Complete the extraLongFactorials function in the editor below. It should print the result and return.

extraLongFactorials has the following parameter(s):

n: an integer

Note: Factorials of $n>20$ can't be stored even in a $64-bit$ long long variable. Big integers must be used for such calculations. Languages like Java, Python, Ruby etc. can handle big integers, but we need to write additional code in C/C++ to handle huge values.

We recommend solving this challenge using BigIntegers.

Input Format

Input consists of a single integer $n$

Constraints

$1\leq n\leq100$

Output Format

Print the factorial of $n$.

Sample Input

$25$

Sample Output

$1551121004330985984000000$

Explanation

$25!=25\times24\times23\times\text{...}\times3\times2\times1$

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