Problems
Goldbach Division
Goldbach Division
Everybody knows Goldbach Conjecture! Here is one edition of it:
1) Every odd integer greater than \textbf{17} can be written as three different odd primes’ sum;
2) Every even integer greater than \textbf{6} can be written as two different odd primes’ sum.
Loving the magical math conjecture very much, iSea try to have a closer look on it. Now he has a new definition: Goldbach Division. If we express an even integer as two different odd primes’ sum, or odd integer as three different odd primes’ sum, we call it a form of Goldbach Division of \textbf{N}, using a symbol \textbf{G}(\textbf{N}).
For example, if \textbf{N} = \textbf{18}, there are two ways to divide \textbf{N}.
\textbf{18} = \textbf{5} + \textbf{13} = \textbf{7} + \textbf{11}
If \textbf{N} = \textbf{19}, there is only one way to divide \textbf{N}.
\textbf{19} = \textbf{3} + \textbf{5} + \textbf{11}
Here comes your task, give a integer \textbf{N}, find |\textbf{G}(\textbf{N})|, the number of different \textbf{G}(\textbf{N}).
\InputFile
There are several test cases in the input.
Each test case includes one integer \textbf{N} (\textbf{1} ≤ \textbf{N} ≤ \textbf{20000}).
The input terminates by end of file marker.
\OutputFile
For each test case, output one integer, indicating |\textbf{G}(\textbf{N})|.
Input example #1
18 19
Output example #1
2 1