/*
    *
    * Prosen Ghosh
    * American International University - Bangladesh (AIUB)
    *
*/

Problem:

Have the function FirstFactorial(num) take the num parameter being passed and return the factorial of it (e.g. if num = 4, return (4 * 3 * 2 * 1)). For the test cases, the range will be between 1 and 18 and the input will always be an integer.

Solution:

function FirstFactorial(num) { 

  for(var i = num-1; i > 0; i--)num*=i;
  return num; 
         
}
   
// keep this function call here 
FirstFactorial(readline());