Permutation, N People Can have R Seats In A Class

def factorial(num):
    fact = 1
    for i in range(num, 1, -1):
        fact *= i
    return fact
# user input
n = int(input("Enter number of people: "))
r = int(input("Enter number of seats: "))
# finding all possible arrangements of n people on r seats
# by using formula of permutation
p = factorial(n) // factorial(n - r)
# printing output
print("Total possible arrangements:", p)