clean up extras folders under documents

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
                )
            )
        )
    )
)