     (distance-try)
 
     (defun distance(p1 p2)
-    (sqrt (+ (square (- (nth 0 p2) (nth 0 p1)))
-            (square (- (nth 1 p2) (nth 1 p1))))))
+        (sqrt (+ (square (- (nth 0 p2) (nth 0 p1)))
+                (square (- (nth 1 p2) (nth 1 p1))))))
 
 
     (distance '(3 5) '(4 2))


;; functions
    (defun say-hello()
    (message "hello!"))
    ;; call function
    (say-hello)

    (defun square(x)
    (* x x))

    (square 5)

    (defun distance-try()
    (sqrt (+ (square (- (car '(4 2)) (car '(3 5))))
            (square (- (nth 1 '(4 2)) (nth 1 '(3 5)))))))

    ;; (+ (square (- (car '(4 2)) (car '(5 3))))
    ;; (square (- (cdr '(4 2)) (cdr '(5 3))))


     (even-or-odd 3)
     (even-or-odd 4)
     (setq blb '2)
     (even-or-odd blb)

     ;; cond is like switch/case in other languages
     (setq n 2)
