feat(4.4.3): Finish U4_L4_Activity_Three

src/main/java/Unit4/U4_L4_Activity_Three.java

@@ -0,0 +1,25 @@
+package Unit4;
+
+import java.util.Scanner;
+
+public class U4_L4_Activity_Three {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        String word1 = scanner.nextLine();
+        String word2 = scanner.nextLine();
+
+        if (word1.length() == word2.length()) {
+
+            for (int i = word1.length(); i > 0; i--) {
+                System.out.print(word2.substring(i - 1, i));
+                System.out.print(word1.substring(i - 1, i));
+            }
+
+        } else {
+            System.out.println("error");
+        }
+
+        scanner.close();
+    }
+}