#
# 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?
#


def isLych(n):
    for _ in range(50):
        n = raa(n)
        if(str(n) == str(n)[::-1]):
            return False
    return True


def raa(n):  # reverse and add
    return n + int(str(n)[::-1])


def main():
    print(sum(1 for i in range(10_000) if(isLych(i))))


if(__name__ == "__main__"):
    main()
