remove kindle unnecessary dirs

kinlde.bat

@echo off
for /f "delims= tokens=1*" %%a in ('dir /b *.sdr') do (
        if not exist "%%~na.mobi" (
                if not exist "%%~na.azw*" (
                        if not exist "%%~na.txt"  (
                                if not exist "%%~na.pdf"  (
                                        rd /s/q %%a
                                )
                        )
                )
        )
)