num1=int(input("Enter a number:"))
def is_prime(num1):
    if num1 <= 1:
        return False
    for i in range (2, int(num1**0.5) + 1):
        if num1 % i == 0:
            return False
    return True
if is_prime(num1):
    print(f"{num1} is a prime number.")
else:
    print(f"{num1} is not a prime number.")