# Secret Handshake > There are 10 types of people in the world: Those who understand > binary, and those who don't. You and your fellow cohort of those in the "know" when it comes to binary decide to come up with a secret "handshake". ```text 1 = wink 10 = double blink 100 = close your eyes 1000 = jump 10000 = Reverse the order of the operations in the secret handshake. ``` Given a decimal number, convert it to the appropriate sequence of events for a secret handshake. Here's a couple of examples: Given the input 3, the function would return the array ["wink", "double blink"] because 3 is 11 in binary. Given the input 19, the function would return the array ["double blink", "wink"] because 19 is 10011 in binary. Notice that the addition of 16 (10000 in binary) has caused the array to be reversed. ## Setup There are two different methods of getting set up to run the tests with Objective-C: - Create an Xcode project with a test target which will run the tests. - Use the ruby gem `objc` as a test runner utility. Both are described in more detail here: http://exercism.io/languages/objective-c ### Submitting Exercises When submitting an exercise, make sure your solution file is in the same directory as the test code. The submit command will look something like: ```shell exercism submit /objective-c/secret-handshake/SecretHandshake.m ``` You can find the Exercism workspace by running `exercism debug` and looking for the line beginning with Workspace. ## Source Bert, in Mary Poppins [http://www.imdb.com/title/tt0058331/quotes/qt0437047](http://www.imdb.com/title/tt0058331/quotes/qt0437047) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.