{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE BinaryLiterals #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NumDecimals #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE FlexibleContexts #-}

{-# OPTIONS_GHC -O2 #-}
{-# OPTIONS_GHC -Wno-tabs #-}

import Control.Applicative
import Control.Arrow
import Control.Monad
import Control.Monad.ST

import Data.Char
import Data.List
import Data.Maybe

import qualified Data.ByteString.Char8 as B

import Data.Array
import Data.Array.ST.Safe
import Data.STRef

import Debug.Trace
import Text.Printf

readInt = fst . fromJust . B.readInt <$> B.getLine
readInteger = fst . fromJust . B.readInteger <$> B.getLine
readInts = map ( fst . fromJust . B.readInt ) . B.words <$> B.getLine
readIntegers = map ( fst . fromJust . B.readInteger ) . B.words <$> B.getLine
readStr = head <$> readStrs
readStrs = map B.unpack . B.words <$> B.getLine

which a b f = if f then a else b
yesno = which "Yes" "No"
mp [ a, b ] = ( a, b )

modifyArray a i f = writeArray a i =<< f <$> readArray a i

printList :: Show a => [a] -> IO ()
printList = putStrLn . intercalate " " . map show

main = do
	n <- readInt
	print $ length $ takeWhile ( <= n ) $ map ( ^ 2 ) [ 1 .. ]