input: Write a function to determine if a number provided by the user is prime or not. The function returns True if the number is prime and False otherwise. The function should handle the case where the input is 1 and return False since 1 is not considered a prime number.
  assert is_prime(17)==True
  assert is_prime(18)==False
  assert is_prime(2)==True
  assert is_prime(1)==False
  assert is_prime(-5)==False
output: def is_prime(n):
      if n <= 1:
          return False
      for i in range(2, int(n**0.5) + 1):
          if n % i == 0:
              return False
      return True