C Masked Global Variable

How would I access the global variable tim from procedure()?

int tim = 0;

void procedure(int tim)
{
    global tim = local tim;
}

But how would i access the global variable tim from inside procedure?

e.g. in a C++ class, it would be like this:

class Jobby{
    int tim = 0;
   
    public void procedure(int tim)
    {
        this.tim = tim;
        // global = local
    }
}