N=int(eval(input()))

while N:

    if N**0.5%1==0:

        print(N)

        break

    else:

        N-=1
N=int(eval(input()))

while N:

    if N**0.5%1==0:print(N);break

    N-=1
N = int(eval(input()))
while N:
    if N**0.5 % 1 == 0:
        print(N)
        break
    else:
        N -= 1

N = int(eval(input()))
while N:
    if N**0.5 % 1 == 0:
        print(N)
        break
    N -= 1

-    else: -        N -= 1 +    N -= 1