def MySqrt (N):         # N must be int or float
    Threshold = 1.0E-12
    Counter = 20
    Guess = N / 2.0
    New = N / Guess
    NewGuess = (Guess + New) / 2.0
    while (abs(Guess - NewGuess) > Threshold) and (Counter > 0):
        Guess = NewGuess
        New = N / Guess
        NewGuess = (Guess + New) / 2.0
        Counter = Counter - 1
    return NewGuess
    
def GetAPositiveNumber (Message):      # Message should be a string
    N = input(Message)
    while (N < 0):
        print "You are an idiot"
        N = input(Message)
    return N
    
def F1 (FROG,TOAD,NEWT):
    SNAKE = FROG + TOAD * NEWT
    return SNAKE

def F2 (CAT=4,DOG=3,ANT=9):
    BOB = F1(DOG,ANT,CAT)
    return BOB
          
  
def SumOfInverses(N):
    Total = 0
    I = 1
    while (I <= N):
        Total = Total + (1/float(I))
        I = I + 1
    return Total