diff --git a/src/one_function_to_rule_them_all.clj b/src/one_function_to_rule_them_all.clj
index 6844d99..ba1b930 100644
--- a/src/one_function_to_rule_them_all.clj
+++ b/src/one_function_to_rule_them_all.clj
@@ -1,43 +1,77 @@
 (ns one-function-to-rule-them-all)
 
 (defn concat-elements [a-seq]
-  :-)
+  (reduce concat [] a-seq))
 
 (defn str-cat [a-seq]
-  :-)
+  (if (empty? a-seq)
+    ""
+    (reduce (fn [str1 str2]
+              (str str1 " " str2))
+            a-seq)))
 
 (defn my-interpose [x a-seq]
-  [:-])
+  (if (empty? a-seq)
+    a-seq
+    (reduce (fn [eka toka]
+              (conj eka x toka)) [(first a-seq)](rest a-seq))))
 
 (defn my-count [a-seq]
-  :-)
+  (reduce (fn [counter seq1]
+            (inc counter)) 0 a-seq))
 
 (defn my-reverse [a-seq]
-  [:-])
+  (reduce (fn [a b]
+            (conj a b)) () a-seq))
 
 (defn min-max-element [a-seq]
-  [:-])
+  (reduce (fn [ret a]
+            (cond
+              (< a (first ret))
+              [a (second ret)]
+              (> a (second ret))
+              [(first ret) a]
+              :else ret))
+          [(first a-seq) (first a-seq)] a-seq))
 
 (defn insert [sorted-seq n]
-  [:-])
+  (sort (conj sorted-seq n)))
 
 (defn insertion-sort [a-seq]
-  [:-])
+  (reduce insert () a-seq))
 
 (defn parity [a-seq]
-  [:-])
+  (reduce (fn [mappi x]
+            (if (odd? (get (frequencies a-seq) x))
+              (conj mappi x)
+              mappi))
+          #{}
+          a-seq))
+
+(defn minus
+  ([x] (- x))
+  ([x y] (- x y)))
 
-(defn minus [x]
-  :-)
+(defn count-params
+  ([x & more]
+  (inc (count more)))
+  ([] 0))
 
-(defn count-params [x]
-  :-)
+(defn my-*
+  ([] 1)
+  ([x] x)
+  ([x y] (* x y))
+  ([x y & more]
+   (reduce my-* (my-* x y) more)))
+
+(defn pred-and ([& more]
+   (fn [x]
+     (if (empty? more)
+       true
+       (reduce (fn [bool pred]
+                 (and bool (pred x))) true more)))))
 
-(defn my-* [x]
-  :-)
 
-(defn pred-and [x]
-  (fn [x] :-))
 
 (defn my-map [f a-seq]
-  [:-])
\ No newline at end of file
+  [:-])