The four joins

The first join: in, ig, ed, eg with lead in

The first join: aw, ap, an, ar with lead in

The second join: ck, ch with lead in

The second join: if, il, it with lead in

The third join: oo, wa, wo with lead in

The third join: on, om, ow with lead in

The fourth join: ob, of, ot, oh with lead in

The fourth join: wl, ok, rt and rl with lead in

The third join: oe, we, ve and re with lead in

The third join: us, rs and ws with lead in