Problem 1702. Maximum value in a matrix

"The program tells me that I'm doing it wrong, even though I think my solution is correct. Can someone tell me why my solution is wrong?
This is my solution:
y = max(A,[],"all")"
I think its all good and i cant see results because I cant summit it bacause it is wrong. I would like to see some solution, there are many problems that i can solve on mathlab editor but they dont work here

@Diego the argument passed to the function is called x here, not A, so you either need to change that to A, or adjust the line of code you give to use x instead of A. Hope this helps!

@Christian Schröder, Thank you very much! That was the problem i had on every single problem. From now it will be different