FA - FE || FA - FB - FC - FD - FE -
FF - FJ || FF - FG - FH - FI - FJ -
FK - FO || FK - FL - FM - FN - FO -
FP - FT || FP - FQ - FR - FS - FT -
FU - FZ || FU - FV - FW - FX - FY - FZ -