2023 AMC 10 B

Define an to be a positive integer of 2 or more digits where the digits are strictly increasing moving left to right. Similarly, define a to be a positive integer of 2 or more digits where the digits are strictly decreasing moving left to right. For instance, the number 258 is an and 8620 is a . Let U equal the total number of and let D equal the total number of . What is|U - D|? (2023 AMC10B Q16)