#!/usr/bin/env python

# If we take 47, reverse and add, 47 + 74 = 121, which is palindromic.
#
# Not all numbers produce palindromes so quickly. For example,
#
# 349 + 943 = 1292,
# 1292 + 2921 = 4213
# 4213 + 3124 = 7337
#
# That is, 349 took three iterations to arrive at a palindrome.
#
# Although no one has proved it yet, it is thought that some numbers,
# like 196, never produce a palindrome. A number that never forms a
# palindrome through the reverse and add process is called a Lychrel
# number. Due to the theoretical nature of these numbers, and for the
# purpose of this problem, we shall assume that a number is Lychrel
# until proven otherwise. In addition you are given that for every
# number below ten-thousand, it will either (i) become a palindrome in
# less than fifty iterations, or, (ii) no one, with all the computing
# power that exists, has managed so far to map it to a palindrome. In
# fact, 10677 is the first number to be shown to require over fifty
# iterations before producing a palindrome:
# 4668731596684224866951378664 (53 iterations, 28-digits).
#
# Surprisingly, there are palindromic numbers that are themselves
# Lychrel numbers; the first example is 4994.
#
# How many Lychrel numbers are there below ten-thousand?
#
# NOTE: Wording was modified slightly on 24 April 2007 to emphasise
# the theoretical nature of Lychrel numbers.


def palindrome_number(n):
    ns=str(n)
    return ns == ns[::-1]

def lychrel(n, lychrel_set=set()):
    wn = n
    for i in xrange(0, 50):
        nl = list(str(wn))
        nl.reverse()
        rn = int("".join(nl))

        wn = wn + rn
        
        if palindrome_number(wn):
            return False

    return True

num = 0
for i in xrange(1, 10000):
    if lychrel(i):
        num += 1

print num
