def get_mvarg(size_pos, position="full"):
    """Take xrandrs size&pos and prepare it for wmctrl (MVARG) format
    
    MVARG: <G>,<X>,<Y>,<W>,<H>
      * <G> - gravity, 0 is default
    """
    allowed = ["left", "right", "top", "bottom", "full"]
    if position not in allowed:
        raise ValueError(f"Position has to be one of {allowed}")
    
    size, x, y = size_pos.split("+")
    w, h = size.split("x")
    
    if position == "left":
        w = int(w) // 2
    if position == "right":
        w = int(w) // 2
        x = int(x) + w
    return f"0,{x},{y},{w},{h}"