N = int(eval(input()))

for i in range(N + 1)[::-1]:

    sqrt = int(i ** (1 / 2))

    if sqrt ** 2 == i:

        print(i)

        break
N = int(eval(input()))

N = int(N ** 0.5)

print((N*N))
N = int(eval(input()))
for i in range(N + 1)[::-1]:
    sqrt = int(i ** (1 / 2))
    if sqrt**2 == i:
        print(i)
        break

N = int(eval(input()))
N = int(N**0.5)
print((N * N))

-for i in range(N + 1)[::-1]: -    sqrt = int(i ** (1 / 2)) -    if sqrt**2 == i: -        print(i) -        break +N = int(N**0.5) +print((N * N))