diff --git a/src/main/java/org/jugbd/marathon/day3/TrappingTheRainWater.java b/src/main/java/org/jugbd/marathon/day3/TrappingTheRainWater.java
index 23b1303..c9c6473 100644
--- a/src/main/java/org/jugbd/marathon/day3/TrappingTheRainWater.java
+++ b/src/main/java/org/jugbd/marathon/day3/TrappingTheRainWater.java
@@ -2,34 +2,34 @@
 
 
 public class TrappingTheRainWater {
-    static int findWaterUnit(int[] arr) {
-    	
-    	int unitOfWater = 0, i, j, k;
-		 boolean checked[] = new boolean[arr.length];
-		 
-		 for(i=0;i<arr.length;i++) {
-			 
-			 checked[i] = false;
-		 }
-		 
-		 for(i=0;i<arr.length;i++) {
-			 
-			 if(checked[i] == false) { 
-			 
-				 for(j=i+1;j<arr.length;j++) {
-					 
-					 if(arr[i] <= arr[j] && checked[j] == false) {
-						 
-						 for(k=i+1;k<j;k++) {
-							 
-							 unitOfWater += (arr[i]-arr[k]);
-							 checked[k] = true;
-						 }
-						 break;
-					 }
-				 }
-			 } 
-		 }
-		 return unitOfWater;
-    }
+	static int findWaterUnit(int[] arr) {
+
+		int unitOfWater = 0, i, j, k;
+		boolean checked[] = new boolean[arr.length];
+
+		for(i=0;i<arr.length;i++) {
+
+			checked[i] = false;
+		}
+
+		for(i=0;i<arr.length;i++) {
+
+			if(checked[i] == false) { 
+
+				for(j=i+1;j<arr.length;j++) {
+
+					if(arr[i] <= arr[j] && checked[j] == false) {
+
+						for(k=i+1;k<j;k++) {
+
+							unitOfWater += (arr[i]-arr[k]);
+							checked[k] = true;
+						}
+						break;
+					}
+				}
+			} 
+		}
+		return unitOfWater;
+	}
 }
diff --git a/src/main/java/org/jugbd/marathon/day4/Directory.java b/src/main/java/org/jugbd/marathon/day4/Directory.java
index 69953ea..9cfeb86 100644
--- a/src/main/java/org/jugbd/marathon/day4/Directory.java
+++ b/src/main/java/org/jugbd/marathon/day4/Directory.java
@@ -1,29 +1,61 @@
 package org.jugbd.marathon.day4;
 
 import java.util.Date;
+import java.util.ArrayList;
 
 public class Directory {
-    private String name;
+	
+	private String name;
     private Date createdDate;
+    private ArrayList<Directory> directoryList; 
+    private ArrayList<File> fileList; 
 
     public Directory(String root) {
+    	
+    	this.name = root;
+    	this.createdDate = new Date();
+    	this.directoryList = new ArrayList<>();
+    	this.fileList = new ArrayList<>();
+    }
+    
+    public void add(Directory directory) {
 
+    	this.directoryList.add(directory);
     }
 
     public void add(File file) {
 
+    	this.fileList.add(file);
+    }
+    
+    public int getAllFileCounts(Directory dir) {
+    	
+    	if(dir.directoryList.size() == 0)
+    		return dir.fileList.size();
+    	
+    	int length = dir.directoryList.size();
+    	int sumOfFiles = 0;
+    	
+    	for(int i = 0; i < length; i++) {
+    		
+    		sumOfFiles += getAllFileCounts(dir.directoryList.get(i));
+    	}
+    	return sumOfFiles + dir.fileList.size();
     }
 
     public int numberOfFiles() {
 
-        return 0;
+        return getAllFileCounts(this);
     }
 
-    public Object getName() {
+    public String getName() {
+    	
         return name;
     }
 
     public Date getCreatedDate() {
+    	
         return createdDate;
     }
+
 }
diff --git a/src/main/java/org/jugbd/marathon/day4/File.java b/src/main/java/org/jugbd/marathon/day4/File.java
index 3ec3cd3..7e94a76 100644
--- a/src/main/java/org/jugbd/marathon/day4/File.java
+++ b/src/main/java/org/jugbd/marathon/day4/File.java
@@ -2,13 +2,16 @@
 
 
 public class File {
-    private String name;
+	
+	private String name;
 
     public File(String name) {
 
+    	this.name = name;
     }
 
     public String getName() {
+    	
         return name;
     }
 }
diff --git a/src/test/java/org/jugbd/marathon/day2/BiggestNumberTest.java b/src/test/java/org/jugbd/marathon/day2/BiggestNumberTest.java
index e11dd53..0552be5 100644
--- a/src/test/java/org/jugbd/marathon/day2/BiggestNumberTest.java
+++ b/src/test/java/org/jugbd/marathon/day2/BiggestNumberTest.java
@@ -16,6 +16,6 @@ public void basicTests() {
         assertEquals(414, BiggestNumber.findTheNextBiggerNumber(144));
         assertEquals(-1, BiggestNumber.findTheNextBiggerNumber(111));
         assertEquals(-1, BiggestNumber.findTheNextBiggerNumber(531));
-        assertEquals(753772, BiggestNumber.findTheNextBiggerNumber(737752));
+        assertEquals(752377, BiggestNumber.findTheNextBiggerNumber(737752));
     }
 }
\ No newline at end of file