Canadian Computing Competition: 2005 Stage 1, Junior #2

When a credit card number is sent through the Internet it must be protected so that other people cannot see it. Many web browsers use a protection based on "RSA Numbers."

A number is an RSA number if it has exactly four divisors. In other words, there are exactly four numbers that divide into it evenly. For example, ~10~ is an RSA number because it has exactly four divisors ~(1, 2, 5, 10)~. ~12~ is not an RSA number because it has too many divisors ~(1, 2, 3, 4, 6, 12)~. ~11~ is not an RSA number either. There is only one RSA number in the range ~10 \dots 12~.

Write a program that inputs a range of numbers and then counts how many numbers from that range are RSA numbers. You may assume that the numbers in the range are less than ~1000~.

Sample Input 1

10
12

Sample Output 1

The number of RSA numbers between 10 and 12 is 1

Sample Input 2

11
15

Sample Output 2

The number of RSA numbers between 11 and 15 is 2