Pair of Primes

Time Limit : 1 sec, Memory Limit : 65536 KB

Pair of Primes

We arrange the numbers between 1 and N (1 <= N <= 10000) in increasing order and decreasing order like this:

1 2 3 4 5 6 7 8 9 . . . N
N . . . 9 8 7 6 5 4 3 2 1

Two numbers faced each other form a pair. Your task is to compute the number of pairs P such that both numbers in the pairs are prime.

Input

Input contains several test cases. Each test case consists of an integer N in one line.

Output

For each line of input, output P .

Sample Input

1
4
7
51

Output for the Sample Input

0
2
2
6

Source: Introduction to AOJ , Aizu-Wakamatsu, Japan
Problem Setter:  team86