Solve the programming task below in a Python markdown code block.
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 .

Example

Input

1
4
7
51


Output

0
2
2
6