def abs(a):
    if a>0:
        return float(a)
    else:
        return float(-a)
def power(num,exp):
    if exp!=0:
        if exp>0:
            ret=num;
            for i in range(1,exp,1):
                ret=ret*num;
            return ret;
        else:
            ret=num;
            for i in range(1,exp,1):
                ret=ret/num;
            return ret;
    else:
        return 1.0;
def root(num,exp):
    if exp>0:
        a=num/2
        b=(1/exp)*((exp-1)*a+(num/power(a,exp-1)))
        delta=abs(b-a)
        while(delta>0.000000000000001):
            a=b
            b=(1/exp)*((exp-1)*a+(num/power(a,exp-1)))
            delta=abs(b-a)
        return b
    else:
        print("das da rong numba")
        return -1.0
def log(num):
    index=6
    a=2*((num-1)/(num+1))
    b=2*((num-1)/(num+1)+power((num-1)/(num+1),3)/3)
    delta=abs(b-a)
    while(delta>0.000001):
        a=b
        b=0
        for i in range(1,index,2):
            b=b+(1/i)*power((num-1)/(num+1),i)
        b=b*2
        delta=delta=abs(b-a)
        index=index+2
    return b
def logswitch(num,baza):
    if baza=="e":
        return log(num)
    else:
        b=float(baza)
        if b<0:
            print("invalid base")
            return -1
        else:
            return log(num)/log(baza)
def benis():
    dec=float(input("number>0: "))
    exp=int(input("positive root: "))
    print(root(dec,exp))
def bagina():
    num=float(input("number>0: "))
    baza=float(input("positive base: "))
    print(logswitch(num,baza))
def check():
    c=input("continue? [Y/N][H-help] ")
    if c=='n' or c=='N':
        return False
    elif c=='y' or c=='Y':
        return True
    elif c=='h' or c=='H':
        print("commands: [log/root] ")
        return check()
    else:
        print("learn how to read")
        return check()
print("your shitty calculator [H-help]")
con=True
instr=""
while(con):
    instr=input("")
    if instr=="log":
        bagina()
    elif instr=="root":
        benis()
    elif instr=="H" or instr=="h":
        print("commands: [log/root] ")
    else:
        print("invalid command")
    con=check()