Problem:
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

Solution in Python (judge verdict: Wrong Answer)

import math
r = 9000
sqrt = int(math.sqrt(r))
p = [1 for i in range(r)]
p[0] = 0
for i in range(sqrt):
    if p[i]:
        p[2*i+1::i+1] = [0 for j in range(2*i+1,r,i+1)]
prime = []
for i in range(r):
    if p[i]:
        prime.append(i)

while True:
    try:
        n = int(raw_input())
        count = 0
        for i in prime:
            if i > n-1:
                break
            if p[i]*p[n-i-1] == 1:
                count += 1
        print count
    except:
        break