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745. Prime sum
Vaqt limiti: 1 sekund
Xotira limiti: 64 MB

 Find all pairs of prime numbers (A, B) such that A<=B and their sum is also a prime number and does not exceed N.

Input

  The input of the problem consists of the only integer N (1<=N<=10^6).

Output      

On the first line of the output file write the number of pairs meeting the requirements.

Samples

Input

Output

1

4

0

2

5

1

 

Tayyorladi: Azat Yusupov
Text from: acm.sgu.ru
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