diff --git a/TravelCostCalculator.java b/TravelCostCalculator.java
index 6f89acb..4643419 100644
--- a/TravelCostCalculator.java
+++ b/TravelCostCalculator.java
@@ -1,3 +1,5 @@
+// Nehara S.A.T. EG/2020/4092
+
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
@@ -6,66 +8,59 @@
 import java.util.Map;
 
 public class TravelCostCalculator {
-    static Map<String, Double> a = new HashMap<>();
-    static Map<String, Double> b = new HashMap<>();
-    static Map<String, Double> c = new HashMap<>();
-
-    static void l1(String file) throws IOException {
-        BufferedReader reader = new BufferedReader(new FileReader(file));
-        String i; 
-        while ((i = reader.readLine()) != null) {
-            String[] p = i.split(",");
-            a.put(p[0].toUpperCase(), Double.parseDouble(p[1]));
-        }
-    }
+    private static final Map<String, Double> hotelRates = new HashMap<>();
+    private static final Map<String, Double> exchangeRates = new HashMap<>();
+    private static final Map<String, Double> flightCosts = new HashMap<>();
 
-    static void l2(String file) throws IOException {
-        BufferedReader reader = new BufferedReader(new FileReader(file));
-        String i;
-        while ((i = reader.readLine()) != null) {
-            String[] p = i.split(",");
-            b.put(p[0].toUpperCase(), Double.parseDouble(p[1]));
+    /**
+     * loads CSV type hotelData to a Map
+     * @param-file contains csv type hotelRates data
+     * @param-Map 
+     */
+    private static void loadHotelRates(String file,Map<String, Double> data) throws IOException {
+        try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                String[] parts = line.split(",");
+                data.put(parts[0].toUpperCase(), Double.parseDouble(parts[1]));
+            }
         }
     }
 
-    static void l3(String file) throws IOException {
-        BufferedReader reader = new BufferedReader(new FileReader(file));
-        String i;
-        while ((i = reader.readLine()) != null) {
-            String[] p = i.split(",");
-            c.put(p[0].toUpperCase(), Double.parseDouble(p[1]));
-        }
-    }
 
     public static void main(String[] args) {
         try {
-            l1("data/hotel_rates.csv");
-            l2("data/exchange_rates.csv");
-            l3("data/flight_costs.csv");
+            loadData("data/hotel_rates.csv", hotelRates);
+            loadData("data/exchange_rates.csv", exchangeRates);
+            loadData("data/flight_costs.csv", flightCosts);
 
             BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
 
             System.out.print("Enter your destination: ");
-            String destination = reader.readLine().toUpperCase();
 
-            double flight_cost = c.getOrDefault(destination, 0.0);
-            double hotel_cost = a.getOrDefault(destination, 0.0);
+            String destination = reader.readLine().toUpperCase();
+            double flightCost = flightCosts.getOrDefault(destination, 0.0);
 
             System.out.print("Enter your stay duration in days: ");
-            int stay_duration = Integer.parseInt(reader.readLine());
-            hotel_cost *= stay_duration;
 
-            double total_cost_usd = flight_cost + hotel_cost;
+            int stayDuration = Integer.parseInt(reader.readLine());
+
+            //hotelCost is calculated by multiplying hotelcost by stay_duration
+            hotelCost *= stay_duration;
+
+            //totalCostUsd is calculated by multiplying hotelcost by stay_duration
+            double totalCostUsd = flightCost + hotelCost;
+
+            System.out.printf("Flight cost: USD %.2f\n", flightCost);
+            System.out.printf("Hotel cost (%d days): USD %.2f\n", stayDuration, hotelCost);
+            System.out.printf("Total: USD %.2f\n", totalCostUsd);
 
-            System.out.printf("Flight cost: USD %.2f\n", flight_cost);
-            System.out.printf("Hotel cost (%d days): USD %.2f\n", stay_duration, hotel_cost);
-            System.out.printf("Total: USD %.2f\n", total_cost_usd);
+            String[] availableCurrencies = exchangeRates.keySet().toArray(new String[0]);
 
-            String[] available_currencies = b.keySet().toArray(new String[0]);
-            System.out.print("Select your currency for final price estimation(" + String.join(", ", available_currencies) + "): ");
-            String selected_currency = reader.readLine();
+            System.out.print("Select your currency for final price estimation(" + String.join(", ", availableCurrencies) + "): ");
 
-            double final_price_local_currency = total_cost_usd * b.get(selected_currency);
+            String selectedCurrency = reader.readLine();
+            double finalPriceLocalCurrency = totalCostUsd * exchangeRates.get(selectedCurrency);
 
             System.out.printf("Total in %s: %.2f\n", selected_currency, final_price_local_currency);
         } catch (IOException e) {