 In order to have life, you need to balance that. That's what's happening in the compost toilet. Carbon. What is the carbon? Carbon is sawdust from our neighbors that have a wood chop here. So instead of that sawdust going into the landfill of Tucson, it comes to my compost toilet. That's the carbon. The oxygen. You do need to air this like every 7 to 10 days. And you air it with...