A number is prime if it is divisible only by one and itself. A number is Double Prime if the number itself and its digits are prime numbers.

Question: Write a program that counts double prime numbers within the given range.

Input specification
You will be given two numbers: x and y which are between 1 and 40,000,000.

Output specification:
Show the number of double primes within the given range. If there is no double prime number, then show 0 (zero).

Explanation: There are four prime numbers between 15 and 30: 17, 19, 23, and 29. But only one of them is double prime: 23.