third

src/System.java

@@ -5,5 +5,16 @@ public class System {
     private ArrayList<Flight> flights ;
 
 
+    public System(){
+
+    }
+
+    public void addFlight(Flight flight){
+        this.flights.add() ;
+    }
+
+    public void removeFlight(Flight flight){
+        this.flights.remove(flight) ;
+    }
 
 }

src/Ticket.java

 public class Ticket {
+
+    private int seatNum ;
+    private int flightNum ;
+    private int luggageWeight ;
+    private Boolean foodStatus ;
+
+    public Ticket(int seatNum , int flightNum , int luggageWeight , boolean foodStatus){
+        this.seatNum = seatNum ;
+        this.flightNum = flightNum ;
+        this.luggageWeight = luggageWeight ;
+        this.foodStatus = foodStatus ;
+    }
+
+    public int getSeatNum(){
+        return seatNum ;
+    }
+
+    public int getFlightNum(){
+        return flightNum ;
+    }
+
+    public int getLuggageWeight(){
+        return luggageWeight ;
+    }
+
+    public Boolean getFoodStatus(){
+        return foodStatus ;
+    }
 }