import math

N = int(eval(input()))



for i in reversed(list(range(N))):

    n = math.sqrt(N)

    if n.is_integer():

        print((int(n ** 2)))

        exit()

    N -= 1
import math



N = int(eval(input()))

n = int(math.sqrt(N))

print((n ** 2))
import math

N = int(eval(input()))
for i in reversed(list(range(N))):
    n = math.sqrt(N)
    if n.is_integer():
        print((int(n**2)))
        exit()
    N -= 1

import math

N = int(eval(input()))
n = int(math.sqrt(N))
print((n**2))

-for i in reversed(list(range(N))): -    n = math.sqrt(N) -    if n.is_integer(): -        print((int(n**2))) -        exit() -    N -= 1 +n = int(math.sqrt(N)) +print((n**2))