input: Write a function to print all the divisors of a given number provided by the user. If the number is less than 1, raise a ValueError.
  assert print_divisors(6) == "The divisors of 6 are: 1, 2, 3, 6"
  assert print_divisors(28) == "The divisors of 28 are: 1, 2, 4, 7, 14, 28"
  assert print_divisors(-5) == ValueError
  assert print_divisors(1) == "The divisors of 1 are: 1"
output: def print_divisors(n):
      if n < 1:
          raise ValueError
      divisors = [str(i) for i in range(1, n + 1) if n % i == 0]
      return f"The divisors of {n} are: " + ", ".join(divisors)