The following text is an in-order traversal of a binary tree with 1023  nodes. What is the sum of the digits appearing in the leaves?How can I improve this Clojure code? It looks strange to me to have two recurs in the if.(ns fun2)(defn parse [in sum] (println sum sum) (if (> (.length in) 1)   (let [next-char (subs in 0 1)]     (if (.matches next-char [0-9])       (recur (subs in 2) (+ sum (Integer/parseInt next-char)))       (recur (subs in 2) sum)))))(parse (slurp /Users/clojure/challange2.txt) 0);; ans 331
Finding the sum of the digits appearing in the leaves via in-order traversal
programming challenge;tree;clojure