A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number.
Enter a natural number, determine whether it is a prime, if it is a prime, “? is a prime number”. Otherwise, print “? is a composite number”. If the input is not a natural number, Please continue to enter another number. To stop entering numbers, press the EOF key.