def is_permutation(num1, num2):
    num1_digits = [0] * 10
    num2_digits = [0] * 10
    while num1 > 0:
        num1_digits[num1 % 10] += 1
        num1 = num1 // 10
    while num2 > 0:
        num2_digits[num2 % 10] += 1
        num2 = num2 // 10
    return num1_digits == num2_digits

def find_all_permutation_pairs(target, to_print = False):
    count = 0
    for i in range(target // 2):
        if is_permutation(i, target - i):
            count += 1
            if to_print:
                print("{} + {} = {}".format(i, target - i, target))
    return count
def most_permutation_pairs(n):
    max_count = 0
    max_i = 0
    for i in range(n+1):
        num_pairs = find_all_permutation_pairs(i)
        if num_pairs > max_count:
            max_count = num_pairs
            max_i = i
    print ("{}: pairs = {}".format(max_i, max_count))
def print_all_pair_counts(n):
    for i in range(n):
        num_pairs = find_all_permutation_pairs(i)
        if num_pairs != 0:
            print("{}: pairs = {}".format(i, num_pairs))