You have a few problems to fix:
As you can see in its documentation, the input function requires you to include some prompting text, such as
you want to loop from 1 to the number of elements in x (not from 1 to x itself). You should be able to figure that out. It is not difficult.
Finally, you keep overwriting the same scalar value of y, over and over. Instead, you also want to define a vector y, and only write to each element in turn. Again, I bet you can figure that out (since you are doing something similar with x).