diff --git a/exp12/Person.java b/exp12/Person.java
new file mode 100644
index 0000000..be3633f
--- /dev/null
+++ b/exp12/Person.java
@@ -0,0 +1,21 @@
+package exp12;
+
+import exp12.TicketingSystem.TicketingSystem;
+
+public class Person extends Thread{
+
+    @Override
+    public void run() {
+        while (true) {
+            try {
+                Thread.sleep(3);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            if ( !TicketingSystem.buy(Thread.currentThread().getName())) {
+                break;
+            }
+        }
+    }
+}
diff --git a/exp12/TicketingSystem/TicketingSystem.java b/exp12/TicketingSystem/TicketingSystem.java
new file mode 100644
index 0000000..010d8d9
--- /dev/null
+++ b/exp12/TicketingSystem/TicketingSystem.java
@@ -0,0 +1,29 @@
+package exp12.TicketingSystem;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class TicketingSystem {
+    private int tickets = 200;
+    private Map<String, Integer> map = new HashMap<>();
+    final int MAX_PERSON = 5;
+    final int MAX_TICKET_PER_PERSON =10;
+
+
+    public static void main(String[] args) {
+        
+    }
+
+    public synchronized boolean buy(String user) {
+        if(!map.containsValue(user) && map.size()<MAX_PERSON) {
+            map.put(user, 1);
+            this.tickets--;
+        }else if(map.get(user) < MAX_PERSON) {
+            
+        }
+
+
+        return false;
+    }
+    
+}
\ No newline at end of file