diff --git a/lab3/OperationsStrings/.idea/.gitignore b/lab3/OperationsStrings/.idea/.gitignore
new file mode 100644
index 0000000..13566b8
--- /dev/null
+++ b/lab3/OperationsStrings/.idea/.gitignore
@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
diff --git a/lab3/OperationsStrings/.idea/.name b/lab3/OperationsStrings/.idea/.name
new file mode 100644
index 0000000..002da1d
--- /dev/null
+++ b/lab3/OperationsStrings/.idea/.name
@@ -0,0 +1 @@
+Main.java
\ No newline at end of file
diff --git a/lab3/OperationsStrings/.idea/misc.xml b/lab3/OperationsStrings/.idea/misc.xml
new file mode 100644
index 0000000..7464918
--- /dev/null
+++ b/lab3/OperationsStrings/.idea/misc.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_19" default="true" project-jdk-name="openjdk-19" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/lab3/OperationsStrings/.idea/modules.xml b/lab3/OperationsStrings/.idea/modules.xml
new file mode 100644
index 0000000..32e9116
--- /dev/null
+++ b/lab3/OperationsStrings/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/OperationsStrings.iml" filepath="$PROJECT_DIR$/OperationsStrings.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/lab3/OperationsStrings/OperationsStrings.iml b/lab3/OperationsStrings/OperationsStrings.iml
new file mode 100644
index 0000000..c90834f
--- /dev/null
+++ b/lab3/OperationsStrings/OperationsStrings.iml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/lab3/OperationsStrings/out/production/OperationsStrings/Main.class b/lab3/OperationsStrings/out/production/OperationsStrings/Main.class
new file mode 100644
index 0000000..97fa6cc
Binary files /dev/null and b/lab3/OperationsStrings/out/production/OperationsStrings/Main.class differ
diff --git a/lab3/OperationsStrings/src/Main.java b/lab3/OperationsStrings/src/Main.java
new file mode 100644
index 0000000..e4e71f0
--- /dev/null
+++ b/lab3/OperationsStrings/src/Main.java
@@ -0,0 +1,25 @@
+import java.util.HashSet;
+
+public class Main {
+
+    public static void main(String[] args) {
+        String inputText = "Who are you? What is your name? Where are you from?";
+        int targetLength = 3;
+
+        try {
+            HashSet<String> uniqueWords = new HashSet<String>();
+            String[] sentences = inputText.split("[?]");
+            for (String sentence : sentences) {
+                String[] words = sentence.trim().split("\\s+");
+                for (String word : words) {
+                    if (word.length() == targetLength) {
+                        uniqueWords.add(word.toLowerCase());
+                    }
+                }
+            }
+            System.out.println("Unique words of length " + targetLength + " in the input text are: " + uniqueWords);
+        } catch (Exception e) {
+            System.out.println("An error occurred: " + e.getMessage());
+        }
+    }
+}
diff --git a/lab3/lab3.pdf b/lab3/lab3.pdf
new file mode 100644
index 0000000..12fb76b
Binary files /dev/null and b/lab3/lab3.pdf differ