How would I find the closest perfect square to a number, without using sqrt?

Python Help
2

Forgot the code sorry

perSqrs = [1,4,9,16,25,36,49,64,81,100]
N = float(input("Number: "))
E = 0
E = min(perSqrs, key=lambda x: abs(x - E))

for i in range(10):
    E = (E + N / E) / 2
    
print(E)
print(E * E)