print('Hello world!')

def square(A,B,C=2):
    k=0
    p=1
    for _ in range(B):
        if (k**C > A):
            while (k**C) > A:
                k -= p
        elif (k**C < A):
            while (k**C) < A:
                k += p
        p *= 0.1
    return k
print(square(2,4,0.5))