"""
Given an integer number n, you have to print the factorial of this number. 

Input Format:
A number n.

Output Format:
Print the factorial of n.

Example:
Input:
4
Output:
24
"""

k = int(input())
fac = 1
for i in range(1,k+1):
    if(k==0):
        break
    fac=fac*i
print(fac)
