Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio

> print(((io.read"*l"):gsub("%w+",function(s)local r=""for i=1,#s do r=("")[s:byte(-i)>96 and"lower"or"upper"](s:sub(i,i))..r end return r end)))
Don't touch that!
Nod't hcuot taht!

> -- should be: Tno'd hcuot taht!