`check50` is not wrong! Please check [this question][1] for more information about `check50`. Make sure you're in the same directory as `mario.c` and this is the command you run to check your program with check50 check50 2014/x/pset1/mario mario.c Also, your input must match the one required by the pset specification page. Here's a sample output per the pset specification page jharvard@appliance (~/Dropbox/pset1): ./mario Height: 8 ## ### #### ##### ###### ####### ######## ######### Notice that you should let the user type in the height on the same line as the prompt `Height: `! [1]: https://cs50.stackexchange.com/questions/1265/how-to-use-check50