from math import *
def f(x):
    return 1.-log(x)

def df(x):
    return -1.0/x

x=3; xp=0
n = 50
i = 0
while i<n and x!=xp:
    i = i + 1
    xp = x
    x = xp-f(xp)/df(xp)

    print "%i: %1.16f  f(x)=%e" %(i, x, f(x))

print "\n\n%1.16f" % x