let rev = 
	let rec aux acc m = 
		if m = 0 then acc else aux (acc * 10 + m mod 10) (m / 10)
	in aux 0
let f n =
	let rec aux a b = match (a = rev a, b = rev b) with
		true, true -> [a; b]
		| true, false -> [a]
		| false, true -> [b]
		| false, false -> aux (a - 1) (b + 1)
	in if n = rev n then [n] else aux (n - 1) (n + 1)
let g n = 
	Printf.printf "入力: %d\n" n;
	List.iter (Printf.printf "出力: %d\n") (f n);
	print_newline ();;
let () = List.iter g [0; 17; 100]

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