Shell programming help

Shell programming help-general Linux technology-Linux programming and kernel information. The following is a detailed description. There are 10 files, A1, A2 ,......, A10
The two folders are jishu and oushu.
Write a shell script. If the file is an even number and A4 (4 is an even number), move it to oushu,
The file is an odd number (A5, 5 is an odd number) and moved to the jishu folder.
How to Write it...
This is what I wrote.
Cat> check. sh
#! /Bin/sh
Ls A * | while (read line );
Do
If ($ line...) // how do I obtain the file number? I won't write ..
Then mv $ line oushu
Else
Mv $ files jishu
Done