import functools

import itertools

import numpy as np

import sys

MAX_INT = int(10e10)

MIN_INT = -MAX_INT

mod = 1000000007

sys.setrecursionlimit(1000000)

def IL(): return list(map(int,input().split()))

def SL(): return input().split()

def I(): return int(sys.stdin.readline())

def S(): return eval(input())



N = I()

ans = [pow(i,2) for i in range(100000) if pow(i,2)<=N]

print((ans[-1]))
import math

import functools

import itertools

import numpy as np

import sys

MAX_INT = int(10e10)

MIN_INT = -MAX_INT

mod = 1000000007

sys.setrecursionlimit(1000000)

def IL(): return list(map(int,input().split()))

def SL(): return input().split()

def I(): return int(sys.stdin.readline())

def S(): return eval(input())



N = I()

ans = int(math.sqrt(N))

print((ans**2))
import functools
import itertools
import numpy as np
import sys

MAX_INT = int(10e10)
MIN_INT = -MAX_INT
mod = 1000000007
sys.setrecursionlimit(1000000)


def IL():
    return list(map(int, input().split()))


def SL():
    return input().split()


def I():
    return int(sys.stdin.readline())


def S():
    return eval(input())


N = I()
ans = [pow(i, 2) for i in range(100000) if pow(i, 2) <= N]
print((ans[-1]))

import math
import functools
import itertools
import numpy as np
import sys

MAX_INT = int(10e10)
MIN_INT = -MAX_INT
mod = 1000000007
sys.setrecursionlimit(1000000)


def IL():
    return list(map(int, input().split()))


def SL():
    return input().split()


def I():
    return int(sys.stdin.readline())


def S():
    return eval(input())


N = I()
ans = int(math.sqrt(N))
print((ans**2))

+import math -ans = [pow(i, 2) for i in range(100000) if pow(i, 2) <= N] -print((ans[-1])) +ans = int(math.sqrt(N)) +print((ans**2))