DWITE Online Computer Programming Contest, February 2006, Problem 5

The number $181$ is a prime palindrome because it is both a prime number and a palindrome. A palindrome is a number that is the same when read forward as backward. Write a program that determines how many prime palindromes there are between two numbers.

The input will contain five sets of data. Each set will contain two integers, $L$ and $U$, the range of numbers to determine the prime palindromes. $2\le L\le U\le 999999$.

The output will contain the number of prime palindromes between $L$ and $U$, inclusive.

Sample Input (3 sets of data only)

2 10
100 200
10000 20000

Sample Output

4
5
26