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
x=map(int, raw_input().split())
#print x[0]
#n=x[0]
result = 1
while x[0] > 1:
	result = result * x[0]
	x[0] = x[0] - 1
	#print n
print result