var x;
{
read(x);
write(x);
}
use var x(y) to bind variable x to address of y
use var x to declare variable x with auto-assign address
a just use it
*a use it as address
you can use if-else(no elseif), while, break, continue
you can use a = expression, a++, a--
you can use +, -
you can use >, <, >=, <=, ==, !=
build-in function read(x), write(x)