Add all things in the circus

src/main/java/Cannon.java

@@ -0,0 +1,11 @@
+public class Cannon extends Equipment {
+
+    public Cannon(int purchasePrice) {
+        super(purchasePrice);
+    }
+
+    @Override
+    public int getValue() {
+        return purchasePrice / 3;
+    }
+}

src/main/java/Equipment.java

@@ -0,0 +1,11 @@
+public abstract class Equipment {
+    protected int purchasePrice;
+
+    public Equipment(int purchasePrice) {
+        this.purchasePrice = purchasePrice;
+    }
+
+    public int getValue() {
+        return purchasePrice;
+    }
+}

src/main/java/Ladder.java

@@ -0,0 +1,11 @@
+public class Ladder extends Equipment {
+
+    public Ladder(int purchasePrice) {
+        super(purchasePrice);
+    }
+
+    @Override
+    public int getValue() {
+        return purchasePrice / 2;
+    }
+}