N = int(eval(input()))



for i in range(N, 0, -1):

    if i ** 0.5 == int(i ** 0.5):

        print(i)

        exit()

N = int(eval(input()))

i = 1

while i * i <= N:

    i += 1



print(((i - 1) ** 2))

N = int(eval(input()))
for i in range(N, 0, -1):
    if i**0.5 == int(i**0.5):
        print(i)
        exit()

N = int(eval(input()))
i = 1
while i * i <= N:
    i += 1
print(((i - 1) ** 2))

-for i in range(N, 0, -1): -    if i**0.5 == int(i**0.5): -        print(i) -        exit() +i = 1 +while i * i <= N: +    i += 1 +print(((i - 1) ** 2))