input: Write a function to compute the factorial of a given integer and print out the result. The function should take an integer as input and return the factorial of that integer.
  
  def factorial(num):
      if num <= 1:
          return 1
      else:
          return num * factorial(num - 1)
  
  n = int(input("Enter a number: "))
  print("Factorial of",n,"is",factorial(n))
  
  assert factorial(7)==5040
  assert factorial(0)==1
  assert factorial(1)==1
  assert factorial(5)==120
output: def factorial(num):
      if num <= 1:
          return 1
      else:
          return num * factorial(num - 1)