A prime number is an integer greater than that has no positive divisors other than and itself.
We call a number megaprime if it is prime and all of its individual digits are prime. For example, is megaprime because it is prime and all its digits ( and ) are prime; however, is not megaprime because it is not prime (it's divisible by and ), and is not megaprime because it has a non-prime digit ( is not prime).
Given two long integers, and , find and print the total number of megaprime numbers in the inclusive range between and .
Input Format
Two space-separated long integers describing the respective values of and .
Constraints
Output Format
Print a long integer denoting the total number of megaprimes in the inclusive interval between and .
Sample Input 0
1 100
Sample Output 0
8
Explanation 0
There are eight megaprime numbers in the inclusive range from to (i.e., , , , , , , , and ), so we print as our answer.