5a4na 4a4n 3a4nab 2a4na 1a4n
gk3n fk3nab ek3na dk3n ck3nab
rt2nab qt2na pt2n ot2nab nt2na
221na 121n 021nab z21na y21n
dc1n cc1nab bc1na ac1n 9b1nab