diff --git a/Calculator.class b/Calculator.class
new file mode 100644
index 0000000..e38a124
Binary files /dev/null and b/Calculator.class differ
diff --git a/Calculator.java b/Calculator.java
index bc5c9f6..6ddb6bd 100644
--- a/Calculator.java
+++ b/Calculator.java
@@ -20,7 +20,7 @@ public class Calculator {
 	 * @return x + y
 	 */
 	public double plus(double x, double y) {
-		return x - y;
+		return x + y;
 	}
 
 	/**