byku[10], kuby[10], beku[9], ubek[9], buki[9], ubki[9], byki[8], beki[7],
buk[8], kub[8], byk[7], kyu[7], bek[6], kei[4], kie[4], kii[4],
bu[6], ku[5], by[5], be[4], bi[4], ki[3], ii[2],
