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:
'''
# Read input from stdin and provide input before running code

name = raw_input('What is your name?\n')
print 'Hi, %s.' % name
'''
#print 'Hello World!'


N=int(input());
sum1=1;
for i in range(1, N+1):
	sum1=sum1*i;

print sum1