Hi I need to return string from `stringify` function, but currently I'm getting lazy seq. Can't wrap my head how to evaluate lazy seq.

So what I need is to have chain call like this:
`(println "Formated: " (fmt (stringify m)))` 

```
(defn stringify [m]
    "Construct string expression"
    (let [res (reduce-kv (fn [acc k v]
                    (let [s (str/join "" [v (name k)])]
                      (if (pos? v)
                        (if (empty? acc)
                          (concat acc ["+" s])
                          (concat acc s))
                        (concat acc s))
                      ))

          "" m)]
      res))

(defn fmt [s]
    "Apply formating rules"
    (-> s
        (.replaceAll "([+-])" " $1 ")
        (println)))

```