number = input("please enter the number:")
number = int(number)
factorial = 1

while number >= 1 :
    factorial = factorial * number
    number = number -1

print(factorial)

# def factorial():
#     number = input("please enter the number:")
#     number = int(number)
#     factorial = 1
#     for index in range(num-1,1)
#         factorial = factorial * index
#     return factorial
#
#
# factorial()
