let sumnum n =
let rec f n ret =
else f (n - 9) (ret ^ "9") in
let rec g n s ret =
if n < 1 then ret
else g (n - 1) (s ^ "0") (s :: ret) in
g 5 (f n "") []
let string_of_list l =
let rec f l ret = match l with
[] -> ret
| [a] -> ret ^ a
| a :: b -> f b (ret ^ a ^ ",") in
(f l "[") ^ "]"
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