diff --git a/.gitignore b/.gitignore
index 031e212..b4e31fe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,4 @@
-*
-!*/
-!*.*
-.vscode
+.vscode/*
 *.in
 *.out
 *.ans
diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index 6103329..0000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,74 +0,0 @@
-{
-	"files.associations": {
-		"iostream": "cpp",
-		"iomanip": "cpp",
-		"ostream": "cpp",
-		"array": "cpp",
-		"atomic": "cpp",
-		"*.tcc": "cpp",
-		"bitset": "cpp",
-		"cctype": "cpp",
-		"cfenv": "cpp",
-		"chrono": "cpp",
-		"cinttypes": "cpp",
-		"clocale": "cpp",
-		"cmath": "cpp",
-		"codecvt": "cpp",
-		"complex": "cpp",
-		"condition_variable": "cpp",
-		"csetjmp": "cpp",
-		"csignal": "cpp",
-		"cstdarg": "cpp",
-		"cstddef": "cpp",
-		"cstdint": "cpp",
-		"cstdio": "cpp",
-		"cstdlib": "cpp",
-		"cstring": "cpp",
-		"ctime": "cpp",
-		"cuchar": "cpp",
-		"cwchar": "cpp",
-		"cwctype": "cpp",
-		"deque": "cpp",
-		"forward_list": "cpp",
-		"list": "cpp",
-		"unordered_map": "cpp",
-		"unordered_set": "cpp",
-		"vector": "cpp",
-		"exception": "cpp",
-		"algorithm": "cpp",
-		"functional": "cpp",
-		"iterator": "cpp",
-		"map": "cpp",
-		"memory": "cpp",
-		"memory_resource": "cpp",
-		"numeric": "cpp",
-		"optional": "cpp",
-		"random": "cpp",
-		"ratio": "cpp",
-		"regex": "cpp",
-		"set": "cpp",
-		"string": "cpp",
-		"string_view": "cpp",
-		"system_error": "cpp",
-		"tuple": "cpp",
-		"type_traits": "cpp",
-		"utility": "cpp",
-		"fstream": "cpp",
-		"future": "cpp",
-		"initializer_list": "cpp",
-		"iosfwd": "cpp",
-		"istream": "cpp",
-		"limits": "cpp",
-		"mutex": "cpp",
-		"new": "cpp",
-		"scoped_allocator": "cpp",
-		"shared_mutex": "cpp",
-		"sstream": "cpp",
-		"stdexcept": "cpp",
-		"streambuf": "cpp",
-		"thread": "cpp",
-		"typeindex": "cpp",
-		"typeinfo": "cpp",
-		"valarray": "cpp"
-	}
-}
\ No newline at end of file
diff --git a/billboard.java b/billboard.java
new file mode 100644
index 0000000..0ba1744
--- /dev/null
+++ b/billboard.java
@@ -0,0 +1,80 @@
+import java.io.*;
+import java.util.*;
+public class billboard {
+	public static void main(String[] args) throws IOException {
+		// initialize file I/O
+		BufferedReader br = new BufferedReader(new FileReader("billboard.in"));
+		PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("billboard.out")));
+		
+		// read in the locations of the first billboard
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		int x1 = Integer.parseInt(st.nextToken());
+		int y1 = Integer.parseInt(st.nextToken());
+		int x2 = Integer.parseInt(st.nextToken());
+		int y2 = Integer.parseInt(st.nextToken());
+		
+		// read in the locations of the second billboard
+		st = new StringTokenizer(br.readLine());
+		int x3 = Integer.parseInt(st.nextToken());
+		int y3 = Integer.parseInt(st.nextToken());
+		int x4 = Integer.parseInt(st.nextToken());
+		int y4 = Integer.parseInt(st.nextToken());
+		
+		// read in the locations of the truck
+		st = new StringTokenizer(br.readLine());
+		int x5 = Integer.parseInt(st.nextToken());
+		int y5 = Integer.parseInt(st.nextToken());
+		int x6 = Integer.parseInt(st.nextToken());
+		int y6 = Integer.parseInt(st.nextToken());
+		
+		// the visible area is the sum of the visible area of the first billboard and the second billboard
+		int combinedArea = visibleArea(x1, y1, x2, y2, x5, y5, x6, y6) + visibleArea(x3, y3, x4, y4, x5, y5, x6, y6);
+		
+		// print the answer
+		pw.println(combinedArea);
+		pw.close();
+	}
+	
+	/**
+	 * Given the lower-left and upper-right corners of a rectangle, return the area of the rectangle
+	 * @param x1 x-coordinate of lower-left corner
+	 * @param y1 y-coordinate of lower-left corner
+	 * @param x2 x-coordinate of upper-right corner
+	 * @param y2 y-coordinate of upper-right corner
+	 * @return area of the rectangle
+	 */
+	public static int areaOfRectangle(int x1, int y1, int x2, int y2) {
+		return (x2-x1)*(y2-y1);
+	}
+	
+	/**
+	 * Given the corners of two rectangles, return the area inside the first rectangle
+	 * but outside the second
+	 * @param x1 x-coordinate of lower-left corner of first rectangle
+	 * @param y1 y-coordinate of lower-left corner of first rectangle
+	 * @param x2 x-coordinate of upper-right corner of first rectangle
+	 * @param y2 y-coordinate of upper-right corner of first rectangle
+	 * @param x3 x-coordinate of lower-left corner of second rectangle
+	 * @param y3 y-coordinate of upper-right corner of second rectangle
+	 * @param x4 x-coordinate of lower-left corner of second rectangle
+	 * @param y4 y-coordinate of upper-right corner of second rectangle
+	 * @return
+	 */
+	public static int visibleArea(int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4) {
+		// start by computing the area that would be visible if there were no second rectangle
+		int visibleArea = areaOfRectangle(x1, y1, x2, y2);
+		
+		// compute the boundaries of the intersection
+		int leftmostBlockedX = Math.max(x1, x3);
+		int rightmostBlockedX = Math.min(x2, x4);
+		int bottommostBlockedY = Math.max(y1, y3);
+		int topmostBlockedY = Math.min(y2, y4);
+		// if the second rectangle does exist, subtract out the area that it blocks
+		if(leftmostBlockedX < rightmostBlockedX && bottommostBlockedY < topmostBlockedY) {
+			visibleArea -= areaOfRectangle(leftmostBlockedX, bottommostBlockedY, rightmostBlockedX, topmostBlockedY);
+		}
+		
+		return visibleArea;
+	}
+	
+}
\ No newline at end of file
diff --git a/measurement.java b/measurement.java
new file mode 100644
index 0000000..9557a5f
--- /dev/null
+++ b/measurement.java
@@ -0,0 +1,60 @@
+import java.io.*;
+import java.util.*;
+public class measurement {
+	public static void main(String[] args) throws IOException {
+		// initialize file I/O
+		BufferedReader br = new BufferedReader(new FileReader("measurement.in"));
+		PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("measurement.out")));
+		
+		// read in all of the notes
+		int n = Integer.parseInt(br.readLine());
+		int[] day = new int[n];
+		String[] cow = new String[n];
+		int[] change = new int[n];
+		for(int i = 0; i < n; i++) {
+			StringTokenizer st = new StringTokenizer(br.readLine());
+			day[i] = Integer.parseInt(st.nextToken());
+			cow[i] = st.nextToken();
+			change[i] = Integer.parseInt(st.nextToken());
+		}
+		
+		// the milk variables track the amount of milk that each cows was last known to produce
+		int bessieMilk = 7, elsieMilk = 7, mildredMilk = 7;
+		// the on variables are true if that cow produced the highest amount of milk on the previous day
+		boolean bessieOn = true, elsieOn = true, mildredOn = true;
+		int dayAdjust = 0;
+		
+		for(int currDay = 1; currDay <= 100; currDay++) {
+			// look through the notes to see if there were any changes on this day
+			for(int i = 0; i < n; i++) {
+				if(day[i] == currDay) {
+					if(cow[i].equals("Bessie")) {
+						bessieMilk += change[i];
+					}
+					if(cow[i].equals("Elsie")) {
+						elsieMilk += change[i];
+					}
+					if(cow[i].equals("Mildred")) {
+						mildredMilk += change[i];
+					}
+				}
+			}
+			// compute the highest milk total and see which cows produced the most milk 
+			int highestMilk = Math.max(bessieMilk, Math.max(elsieMilk, mildredMilk));
+			boolean bessieOnNext = bessieMilk == highestMilk;
+			boolean elsieOnNext = elsieMilk == highestMilk;
+			boolean mildredOnNext = mildredMilk == highestMilk;
+			if(bessieOn != bessieOnNext || elsieOn != elsieOnNext || mildredOn != mildredOnNext) {
+				dayAdjust++;
+			}
+			bessieOn = bessieOnNext;
+			elsieOn = elsieOnNext;
+			mildredOn = mildredOnNext;
+		}
+
+		// print the answer
+		pw.println(dayAdjust);
+		pw.close();
+	}
+
+}
\ No newline at end of file
diff --git a/shuffle.java b/shuffle.java
new file mode 100644
index 0000000..70f66a3
--- /dev/null
+++ b/shuffle.java
@@ -0,0 +1,49 @@
+import java.io.*;
+import java.util.*;
+public class shuffle {
+	public static void main(String[] args) throws IOException {
+		// initialize file I/O
+		BufferedReader br = new BufferedReader(new FileReader("shuffle.in"));
+		PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("shuffle.out")));
+		
+		// read in the number of cows
+		int n = Integer.parseInt(br.readLine());
+		
+		// if a cow was in position i after shuffling, then moveTo[i] will
+		// be the location that they were in before the shuffle
+		int[] moveTo = new int[n+1];
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		for(int i = 1; i <= n; i++) {
+			// destination is the location a cow would be after a shuffle
+			// if they were originally in position i
+			int destination = Integer.parseInt(st.nextToken());;
+			moveTo[destination] = i;
+		}
+		
+		// allocate an array to store the observed locations of all cows
+		// read in the observations
+		int[] finalLocs = new int[n+1];
+		st = new StringTokenizer(br.readLine());
+		for(int i = 1; i <= n; i++) {
+			finalLocs[i] = Integer.parseInt(st.nextToken());
+		}
+		
+		// allocate an array to store the original locations of all cows
+		int[] originalLocations = new int[n+1];
+		for(int finalPosition = 1; finalPosition <= n; finalPosition++) {
+			int currentLocation = finalPosition;
+			// reverse three shuffles
+			for(int iter = 1; iter <= 3; iter++) {
+				currentLocation = moveTo[currentLocation];
+			}
+			// store the original location of the cow that ended up in finalPosition
+			originalLocations[currentLocation] = finalLocs[finalPosition];
+		}
+		
+		// print the answer
+		for(int i = 1; i <= n; i++) {
+			pw.println(originalLocations[i]);
+		}
+		pw.close();
+	}
+}
\ No newline at end of file