题解 | #求解立方根#

while True:
    try:
        val = float(input())
        if abs(val)<=20:
            if val>= 0:
                print(r"{:.1f}".format(val**(1/3)))
            else:
                val = abs(val)
                print(r"-{:.1f}".format(val**(1/3)))
                        
    except:
        break