Selfermodif

there is some commands

commands

x, replaces itself with the code after it ending at X reversed, aka x123X would turn into 321123X
X, for the x command, it does the same thing but with the thing reversed
y, replaces itself with the recently replaced reversed, aka x123Xy would turn into 321123X123
z, reverses one step of replacing, aka x123Xz would turn into x123Xz
w, turns into the last command ran, note also ran at the same time, with the pair and the code in it,
aka x123Xw would turn into 321123X321123X
the commands are ran in order from left to right
anything that weren't this is a comment, the letters xyzw were chosen because they are commonly not used,
other than y

program that is cool

xyzyzXwxwwwwwwwwwwwwwwwwwwwwwwwwwXzzzzzyy