##s = 0
##s = s + 1
##s = s + 2
##s = s + 3
##s = s + 4
##s = s + 5
##s = s + 6
##s = s + 7
##s = s + 8
##s = s + 9
##s = s + 10
##print("The sum is", s)

############整数求和############

##s = 0
##for n in range(1, 11):
##    s = s + n
##
##print("The sum is", s)


############等差整数求和#########

##a = int(input("Start from: "))
##b = int(input("End at: "))
##c = int(input("Step: "))
##
##s = 0
##for n in range(a, b+1, c):
##    s = s + n
##
##print("The sum is", s)

##########摄氏到华氏的转换########

##begin = int(input("Start from: "))
##end = int(input("End at: "))
##step = int(input("Step: "))
##
##for x in range(begin, end, step) :
##    print(x, "->", x * 9 / 5 + 32)


#############求阶乘##############

##n = int(input("Factorial for: "))
##
##prod = 1
##for i in range(2, n+1):
##    prod = prod * i
##
##print("The factorial of", n, "is", prod)

############# 求阶乘, 重复3次 ##############

##for i in range(3):
##    n = int(input("Factorial for: "))
##
##    prod = 1
##    for j in range(2, n+1):
##        prod = prod * j
##
##    print("The factorial of", n, "is", prod)

##########摄氏到华氏的转换, while 版本########

##begin = int(input("Start from: "))
##end = int(input("End at: "))
##step = int(input("Step: "))
##
##x = begin
##while x <= end:
##    print(x, "->", x * 9 / 5 + 32)
##    x = x + step

#############求阶乘, while 版本##############

##n = int(input("Factorial for: "))
##
##prod = 1
##i = 2
##while i <= n:
##    prod = prod * i
##    i = i + 1
##
##print("The factorial of", n, "is", prod)

#############求阶乘计算器，负数结束##############

##print("This is a factorial calculator. -1 to stop.")
##n = int(input("Factorial for: "))
##
##while n >= 0:
##    prod = 1
##    i = 2
##    while i <= n:
##        prod = prod * i
##        i = i + 1
##
##    print("The factorial of", n, "is", prod)
##    
##    n = int(input("Factorial for: "))

#############求平方根(XXX! 会无穷循环，不能终止)#############

##x = float(input("Square root for: "))
##
##guess = 1.0
##
##while guess * guess != x:
##    guess = (guess + x/guess)/2
##
##print(guess)

#######（可以用 ctrl-c 中断计算）

#############求平方根#############
### abs is a build-in standard function

##x = float(input("Square root for: "))
##
##guess = 1.0
##
##while abs(guess * guess - x) > 1e-8:
##    guess = (guess + x/guess)/2
##
##print(guess)

#############求平方根，带显示过程###########
### abs is a build-in standard function

x = float(input("Square root for: "))

guess = 1.0
n = 0

while abs(guess * guess - x) > 1e-12:
    guess = (guess + x/guess)/2
    n = n + 1
    print(n, guess)

print(guess)