#!/usr/bin/python3
# mari von steinkirch @2013
# steinkirch at gmail



def is_palindrome(s):
    return s == reverse(s)

def reverse(s):
    rev = 0
    while s > 0:
        rev = 10*rev + s%10
        s = s//10
    return rev


def is_palindrome_2(s):
    # to use it you need to cast str() first
    while s:
        if s[0] != s[-1]: return False
        else:
            s = s[1:-1] 
            is_palindrome(s)
    return True


def larg_palind_product(n):
    nmax, largpal = 9, 0
    for i in range(1, n):
       nmax += 9*10**i
    for i in range(nmax, nmax//2, -1):
        for j in range(i -1, (i -1)//2, -1):
            candidate = i*j
            if is_palindrome(candidate) and candidate > largpal:
                largpal = candidate
    return largpal


def test_larg_palind_product():
    assert(larg_palind_product(2)== 9009)
    print(larg_palind_product(3))
    print('Tests Passed!')
            
if __name__ == '__main__':
    test_larg_palind_product()