????????
      ----------
WGMYR ) MHYQNHXU
       -GGYFU
        =====
         RLRXH
        -GGYFU
         =====
         HGXMFX
        -HGMJQP
         ======
           TFTGU
          -TLWMJ
           =====
           ?????

base: 15
symbols: FGHJLMNPQRTUWXY
difficulty: medium