In C++

Write a program to list non-prime numbers from 1 to an upperbound the user specifies. A prime number is a positive natural number that has only two positive natural number divisors - one and itself. The number 1 is not a prime number by definition - it has only one divisor. The number 0 is not a prime number - it is not a positive number and has infinite number of divisors. List of prime numbers from 1 to 15 are 2, 3, 5, 7, 11, 13. Ex: The number 15 has divisors of 1, 3, 5, 15 because: 15/1=15, 15/3=5, 15/5=3, 15/15=1, so 15 is not a prime number. The number 13 has only two divisors of 1, 13. 13/1=13, 13/13=1, so 13 is a prime number.