diff --git a/commander/src/main/java/module-info.java b/commander/src/main/java/module-info.java
index 0a750cc2..dffe95c9 100644
--- a/commander/src/main/java/module-info.java
+++ b/commander/src/main/java/module-info.java
@@ -1,6 +1,7 @@
 module hse.java.commander {
     requires javafx.controls;
     requires javafx.fxml;
+    requires static lombok;
 
     opens hse.java.commander to javafx.fxml;
     exports hse.java.commander;
diff --git a/src/main/java/hse/java/lectures/lecture3/tasks/atm/Atm.java b/src/main/java/hse/java/lectures/lecture3/tasks/atm/Atm.java
index 08f551e4..e6e5b1c6 100644
--- a/src/main/java/hse/java/lectures/lecture3/tasks/atm/Atm.java
+++ b/src/main/java/hse/java/lectures/lecture3/tasks/atm/Atm.java
@@ -32,14 +32,68 @@ public static Denomination fromInt(int value) {
     public Atm() {
     }
 
-    public void deposit(Map<Denomination, Integer> banknotes){}
+    public void deposit(Map<Denomination, Integer> banknotes) {
+        if (banknotes == null || banknotes.isEmpty()) {
+            throw new InvalidDepositException("Deposit is empty");
+        }
+
+        for (Map.Entry<Denomination, Integer> entry : banknotes.entrySet()) {
+            if (entry.getKey() == null) {
+                throw new InvalidDepositException("Invalid denomination");
+            }
+            if (entry.getValue() == null || entry.getValue() <= 0) {
+                throw new InvalidDepositException("Invalid banknote count: " + entry.getValue());
+            }
+        }
+
+        for (Map.Entry<Denomination, Integer> entry : banknotes.entrySet()) {
+            this.banknotes.merge(entry.getKey(), entry.getValue(), Integer::sum);
+        }
+    }
 
     public Map<Denomination, Integer> withdraw(int amount) {
-        return Map.of();
+        if (amount <= 0) {
+            throw new InvalidAmountException("Amount must be positive");
+        }
+        int balance = getBalance();
+        if (amount > balance) {
+            throw new InsufficientFundsException("Not enough money in ATM");
+        }
+
+        Map<Denomination, Integer> temp = new EnumMap<>(banknotes);
+        Map<Denomination, Integer> res = new EnumMap<>(Denomination.class);
+
+        List<Denomination> denoms = new ArrayList<>(Arrays.asList(Denomination.values()));
+        denoms.sort((a, b) -> Integer.compare(b.value(), a.value()));
+
+        int ost = amount;
+
+        for (Denomination denom : denoms) {
+            int able = temp.getOrDefault(denom, 0);
+            int need = ost / denom.value();
+            int take = Math.min(able, need);
+
+            if (take > 0) {
+                res.put(denom, take);
+                ost -= take * denom.value();
+            }
+        }
+        if (ost != 0) {
+            throw new CannotDispenseException("Not able to process");
+        }
+        for (Map.Entry<Denomination, Integer> entry : res.entrySet()) {
+            banknotes.merge(entry.getKey(), -entry.getValue(), Integer::sum);
+        }
+
+        return res;
     }
 
     public int getBalance() {
-        return 0;
+        int sum = 0;
+        for (Map.Entry<Denomination, Integer> entry : banknotes.entrySet()) {
+            sum += entry.getKey().value() * entry.getValue();
+        }
+        return sum;
     }
 
 }
diff --git a/src/main/java/hse/java/lectures/lecture3/tasks/html/HtmlDocument.java b/src/main/java/hse/java/lectures/lecture3/tasks/html/HtmlDocument.java
index 1ddf27bf..cb841760 100644
--- a/src/main/java/hse/java/lectures/lecture3/tasks/html/HtmlDocument.java
+++ b/src/main/java/hse/java/lectures/lecture3/tasks/html/HtmlDocument.java
@@ -9,7 +9,6 @@
 import java.util.Set;
 
 public class HtmlDocument {
-
     public HtmlDocument(String filePath) {
         this(Path.of(filePath));
     }
@@ -27,6 +26,105 @@ private String readFile(Path filePath) {
         }
     }
 
-    private void validate(String content){}
+    private void validate(String content) {
+        Deque<String> stack = new ArrayDeque<>();
+        Set<String> tags = Set.of("html", "head", "body", "div", "p");
+        boolean opened = false;
+        boolean closed = false;
+        boolean head = false;
+        boolean body = false;
+
+        int i = 0;
+        while (i < content.length()) {
+            if (content.charAt(i) == '<') {
+                int j = content.indexOf('>', i);
+                if (j == -1) {
+                    throw new RuntimeException();
+                }
+
+                String tag = content.substring(i + 1, j).trim();
+
+                boolean closing_tag = tag.startsWith("/");
+                String tag_name;
+                if (closing_tag) {
+                    tag_name = tag.substring(1).trim().toLowerCase();
+                } else {
+                    String[] parts = tag.split("\\s+");
+                    tag_name = parts[0].toLowerCase();
+                }
+
+                if (!tags.contains(tag_name)) {
+                    throw new UnsupportedTagException("Unsupported tag: " + tag_name);
+                }
+
+                if (closing_tag) {
+                    if (stack.isEmpty()) {
+                        throw new UnexpectedClosingTagException("Unexpected closing tag: " + tag_name);
+                    }
+
+                    String expected = stack.pop();
+                    if (!expected.equals(tag_name)) {
+                        throw new MismatchedClosingTagException("Mismatched closing tag");
+                    }
+
+                    if (tag_name.equals("html")) {
+                        closed = true;
+                    }
+
+                } else {
+                    if (closed) {
+                        throw new InvalidStructureException("Invalid structure");
+                    }
 
-}
+                    if (tag_name.equals("html")) {
+                        if (opened) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                        if (!stack.isEmpty()) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                        opened = true;
+                    } else {
+                        if (!opened) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                    }
+                    if (tag_name.equals("head") || tag_name.equals("body")) {
+                        if (stack.isEmpty() || !stack.peek().equals("html")) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                    }
+
+                    if (tag_name.equals("head")) {
+                        if (head) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                        if (body) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                        head = true;
+                    }
+
+                    if (tag_name.equals("body")) {
+                        if (body) {
+                            throw new InvalidStructureException("Invalid structure");
+                        }
+                        body = true;
+                    }
+                    stack.push(tag_name);
+                }
+                i = j + 1;
+            } else {
+                i++;
+            }
+        }
+
+        if (!stack.isEmpty()) {
+            throw new UnclosedTagException("Unclosed tags");
+        }
+
+        if (!opened || !closed) {
+            throw new InvalidStructureException("Invalid structure");
+        }
+    }
+}
\ No newline at end of file