diff --git a/src/Lab3.java b/src/Lab3.java
index 1bf2cf0..4d5c3f1 100644
--- a/src/Lab3.java
+++ b/src/Lab3.java
@@ -1,6 +1,11 @@
 public class Lab3 {
     public static void main(String[] args) {
         String s = "ASD";
+
+        StringBuilder stringBuilder = new StringBuilder("ASD");
+
+        stringBuilder.append("A");
+
         String s2 = s;
         System.out.println("s2 = " + s2);
         System.out.println(s == s2); // true?
@@ -18,8 +23,13 @@ public class Lab3 {
 
 //      String Pool
         String s4 = "ASD";
-        System.out.println(s4 == s2); // true?
-        System.out.println(s4.equals(s2)); // (true)
+//        String s5 = new String("ASD");
+        String s5 = "AS";
+        s5 += "D";
+        System.out.println(s4 == s5); // true? (SP)
+        System.out.println(s4.equals(s5)); // (true)
+
+
 
         System.out.println("Done!");
     }
diff --git a/src/lab4/Main.java b/src/lab4/Main.java
new file mode 100644
index 0000000..2e69f00
--- /dev/null
+++ b/src/lab4/Main.java
@@ -0,0 +1,7 @@
+package lab4;
+
+public class Main {
+    public static void main(String[] args) {
+        //todo equals+hashcode
+    }
+}