题解 | #求解立方根#

s = float(input().strip())
i = 0.01
if s > 0:
    while i*i*i <= s:
        i += 0.01
    print('%.1f' %i)
else:
    s1 = - s
    while i*i*i <= s1:
        i += 0.01
    print('%.1f' %-i)