Problem: You have been given a positive integer N. You need to find and print the Factorial  of this number. The Factorial of a positive integer N refers to the product of all number in the range from 1 to N. You can read more about the factorial of a number here.

Input Format:
The first and only line of the input contains a single integer N denoting the number whose factorial you need to find. 

Output Format
Output a single line denoting the factorial of the number N.

Constraints
 1 ≤ N ≤ 10   

SAMPLE INPUT
2

SAMPLE OUTPUT
2

Solution (in PYTHON):

Solution:
def fun(n):
	if n==1 or n==0:
		return 1
	else:
		return fun(n-1)*n
n=int(raw_input())
print fun(n)