fff ffi ffk ffo fft fif fii fik fit fkf fki fkk fkt fof foi fok foo fot ftf fti ftk fto ftt i-f iff ifi ifo ift iif iii iio iit ikf iki ikk iko ikt io- iof ioi ioo iot itf iti itk ito itt k-t kff kfi kfo kif kii kik kio kit kki kkk kkt kof koi kok koo kot ktf ktk kto ktt o-i of- off ofi ofo oft oif oii oik oio oit oki okk oko oo- oof ooi ook ooo oot ot- otf oti otk oto ott tff tfi tfk tfo tft tif tii tik tio tit tkk tko tkt to- tof toi tok too tot ttf tti ttk tto ttt