diff --git a/Cars.java b/Cars.java
new file mode 100644
index 0000000..2b63bb0
--- /dev/null
+++ b/Cars.java
@@ -0,0 +1,22 @@
+import java.util.*;
+public class Main {
+    public static void main(String[] args) {
+        Queue<String> Cars = new LinkedList<>();
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        for (int i = 0; i < n; i++){
+            Cars.add(sc.next());
+        }
+
+        for (int i = 0; i < n; i++){
+            System.out.println(Cars.poll());
+        }
+
+        if (Cars.isEmpty()) {
+            System.out.println("is empty");
+        }
+        else {
+            System.out.println("is not empty");
+        }
+    }
+}
diff --git a/Detective.java b/Detective.java
index 5707416..a1c074a 100644
--- a/Detective.java
+++ b/Detective.java
@@ -1,35 +1,44 @@
- 
 import java.util.ArrayList;
 
 class ToDos {
-    
-  public static void main(String[] args) {
-    
-    // Sherlock
-    ArrayList<String> sherlocksToDos = new ArrayList<String>();
-    
-    sherlocksToDos.add("visit the crime scene");
-    sherlocksToDos.add("play violin");
-    sherlocksToDos.add("interview suspects");
-    sherlocksToDos.add("solve the case");
-    sherlocksToDos.add("apprehend the criminal");
-    
-    // Poirot
-    ArrayList<String> poirotsToDos = new ArrayList<String>();
-    
-    poirotsToDos.add("visit the crime scene");
-    poirotsToDos.add("interview suspects");
-    poirotsToDos.add("let the little grey cells do their work");
-    poirotsToDos.add("trim mustache");
-    poirotsToDos.add("call all suspects together");
-    poirotsToDos.add("reveal the truth of the crime");
-    
-    // Print the size of each ArrayList below:
-
-    
-      
-    // Print the name of the detective with the larger to-do list:
-    
-  }
-  
+
+    public static void main(String[] args) {
+
+        // Sherlock
+        ArrayList<String> sherlocksToDos = new ArrayList<String>();
+
+        sherlocksToDos.add("visit the crime scene");
+        sherlocksToDos.add("play violin");
+        sherlocksToDos.add("interview suspects");
+        sherlocksToDos.add("solve the case");
+        sherlocksToDos.add("apprehend the criminal");
+
+        // Poirot
+        ArrayList<String> poirotsToDos = new ArrayList<String>();
+
+        poirotsToDos.add("visit the crime scene");
+        poirotsToDos.add("interview suspects");
+        poirotsToDos.add("let the little grey cells do their work");
+        poirotsToDos.add("trim mustache");
+        poirotsToDos.add("call all suspects together");
+        poirotsToDos.add("reveal the truth of the crime");
+
+        // Print the size of each ArrayList below:
+        int Sherlock = sherlocksToDos.size();
+        int Poirot = poirotsToDos.size();
+        System.out.println(Sherlock);
+        System.out.println(Poirot);
+
+
+        // Print the name of the detective with the larger to-do list:
+
+        if(Sherlock > Poirot) {
+            System.out.println("Sherlock");
+        }
+        else {
+            System.out.println("Poirot");
+        }
+
+    }
+
 }
diff --git a/HashCollisionChecker.java b/HashCollisionChecker.java
index 80631a7..4edc570 100644
--- a/HashCollisionChecker.java
+++ b/HashCollisionChecker.java
@@ -2,14 +2,20 @@
 
 public class HashCollisionChecker {
     public static <T> int countOfUniqueHashCodes(HashSet<T> set) {
-        // TODO: Implement
-        return 0;
+        HashSet<Integer> uniqueHashCodes = new HashSet<>();
+        for (T item : set) {
+            uniqueHashCodes.add(item.hashCode());
+        }
+        return uniqueHashCodes.size();
     }
-
     public static <K, V> int countOfUniqueHashCodes(HashMap<K, V> map) {
-        // TODO: Implement
-        return 0;
+        HashSet<Integer> uniqueHashCodes = new HashSet<>();
+        for (K key : map.keySet()) {
+            uniqueHashCodes.add(key.hashCode());
+        }
+        return uniqueHashCodes.size();
     }
+}
 
     public static void main(String[] args) {
         HashSet<String> set = new HashSet<>();
@@ -18,12 +24,12 @@ public static void main(String[] args) {
         set.add("c#c#c#c#c#c#bBc#c#c#c#c#aa");
         set.add("1234");
         set.add("c#c#c#c#c#c#bBc#c#c#c#c#bB");
-        System.out.println(countOfUniqueHashCodes(set)); // 3
+        System.out.println(HashCollisionChecker.countOfUniqueHashCodes(set)); // 3
 
         HashMap<String, Integer> map = new HashMap<>();
         map.put("c#c#c#c#c#c#c#aaaaaaaabBbB", 14);
         map.put("c#c#c#c#c#c#c#aaaaaaaac#c#", 12);
         map.put("c#c#c#c#c#c#c#aaaaaaaac#cc", 16);
-        System.out.println(countOfUniqueHashCodes(map)); // 2
+        System.out.println(HashCollisionChecker.countOfUniqueHashCodes(map)); // 2
     }
 }
diff --git a/Shuffle.java b/Shuffle.java
new file mode 100644
index 0000000..eb68aa9
--- /dev/null
+++ b/Shuffle.java
@@ -0,0 +1,13 @@
+import java.util.LinkedList;
+import java.util.Collections;
+public class Main {
+    public static void main(String[] args) {
+        LinkedList<Integer> linkedList = new LinkedList<>();
+        linkedList.add(1);
+        linkedList.add(2);
+        linkedList.add(3);
+        linkedList.add(4);
+        Collections.shuffle(linkedList);
+        System.out.println(linkedList);
+    }
+}
diff --git a/University.java b/University.java
new file mode 100644
index 0000000..d799697
--- /dev/null
+++ b/University.java
@@ -0,0 +1,73 @@
+public class Student implements Comparable<Student> {
+    private String Name;
+    private int ID;
+    private Double GPA;
+    public Student (String Name, int ID, Double GPA){
+        this.Name = Name;
+        this.ID = ID;
+        this.GPA = GPA;
+    }
+    public String getName() {
+        return Name;
+    }
+    public void setName(String Name){
+        this.Name = Name;
+    }
+    public int getID() {
+        return ID;
+    }
+    public void setID(int ID) {
+        this.ID = ID;
+    }
+    public Double getGPA() {
+        return GPA;
+    }
+    public void setGPA(Double GPA) {
+        this.GPA = GPA;
+    }
+
+    public int compareTo(Student other) {
+        return Integer.compare(this.ID, other.ID);
+    }
+    public String toString() {
+        return "Name: " + Name + ", Student ID: " + ID + ", GPA: " + GPA;
+    }
+}
+
+import java.util.Scanner;
+import java.util.TreeSet;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        TreeSet<Student> students = new TreeSet<>();
+
+        System.out.println("Enter number of students:");
+        int numberOfStudents = sc.nextInt();
+        sc.nextLine();
+        for (int i = 0; i < numberOfStudents; i++) {
+            System.out.println("Student " + (i + 1) + ":");
+            System.out.print("Name: ");
+            String Name = sc.nextLine();
+            System.out.print("Student ID: ");
+            int ID = sc.nextInt();
+            System.out.print("GPA: ");
+            double GPA = sc.nextDouble();
+            sc.nextLine();
+
+            students.add(new Student(Name, ID, GPA));
+        }
+
+        System.out.print("Enter student ID to search: ");
+        int searchID = sc.nextInt();
+        Student searchStudent = new Student("", searchID, 0.0);
+
+        Student result = students.ceiling(searchStudent);
+
+        if (result != null && result.getID() == searchID) {
+            System.out.println("Student found: " + result);
+        } else {
+            System.out.println("Student not found.");
+        }
+    }
+}