@ECHO OFF
:: Square root (integer results only)
:: Usage:  Sqrt num
:: E.g. SQRT 64 = 8
IF     "%~1"=="" EXIT /B 1
IF NOT "%~2"=="" EXIT /B 1

SETLOCAL ENABLEDELAYEDEXPANSION
SET /A Num = %~1
IF %Num% NEQ %~1 (ENDLOCAL & EXIT /B 1)
IF %Num% LSS   0 (ENDLOCAL & EXIT /B 1)
IF %Num% LSS   2 (ECHO %Num%& ENDLOCAL & EXIT /B 0)
SET Error=0
SET Found=0
SET /A "UBound = ( %Num% + 1 ) / 2"
FOR /L %%A IN (0,1,%UBound%) DO (
	IF !Error! EQU 0 (
		IF !Found! EQU 0 (
			FOR /F %%B IN ('SET /A %%A * %%A') DO (
				IF %~1 LSS %%B (
					SET Error=1
				) ELSE (
					IF %~1 EQU %%B (
						ECHO.%%A
						SET Found=1
					)
				)
			)
		)
	)
)
ENDLOCAL & EXIT /B %Error%