diff --git a/naloge/naloga1/src/Naloga1.java b/naloge/naloga1/src/Naloga1.java
index cbb2629..840ff67 100644
--- a/naloge/naloga1/src/Naloga1.java
+++ b/naloge/naloga1/src/Naloga1.java
@@ -1,19 +1,14 @@
 import java.util.Scanner;
 
 public class Naloga1 {
-    public static void main(String[] args) {
-        Calculator calculator;
-        try {
-            calculator = new Calculator();
+    public static void main(String[] args) throws CollectionException {
+        Calculator calculator = new Calculator();
 
-            Scanner scanner = new Scanner(System.in);
-            while (scanner.hasNextLine()) {
-                calculator.reset();
-                String line = scanner.nextLine();
-                calculator.run(line);
-            }
-        } catch (CollectionException e) {
-            System.out.println(e.getMessage());
+        Scanner scanner = new Scanner(System.in);
+        while (scanner.hasNextLine()) {
+            calculator.reset();
+            String line = scanner.nextLine();
+            calculator.run(line);
         }
     }
 }
@@ -235,7 +230,7 @@ class Calculator {
     }
 
     void len() throws CollectionException {
-        mainStack.push(String.valueOf(mainStack.pop().length()));
+        pushInt(mainStack.pop().length());
     }
 
     void neq() throws CollectionException {
@@ -270,32 +265,38 @@ class Calculator {
 
     void sub() throws CollectionException {
         int right = popInt();
-        pushInt(popInt() - right);
+        int left = popInt();
+        pushInt(left - right);
     }
 
     void mul() throws CollectionException {
-        pushInt(popInt() * popInt());
+        int right = popInt();
+        int left = popInt();
+        pushInt(left * right);
     }
 
     void div() throws CollectionException {
         int right = popInt();
-        pushInt(popInt() / right);
+        int left = popInt();
+        pushInt(left / right);
     }
 
     void mod() throws CollectionException {
         int right = popInt();
-        pushInt(popInt() % right);
+        int left = popInt();
+        pushInt(left % right);
     }
 
     void concat() throws CollectionException {
         String right = mainStack.pop();
-        mainStack.push(mainStack.pop() + right);
+        String left = mainStack.pop();
+        mainStack.push(left + right);
     }
 
     void rnd() throws CollectionException {
         int y = popInt();
         int x = popInt();
-        pushInt((int) (Math.random() * (y - x + 1) + x));
+        pushInt((int) Math.round(Math.random() * (y - x) + x));
     }
 
     void then() throws CollectionException {