????????
      +---------
THTPG | LLHFHFQL
       -PGPFW
        =====
         YLGJF
        -PGPFW
         =====
         TYRPQQ
        -TYJTNT
         ======
           PMWHL
          -THTPG
           =====
           ?????

base: 13
letters: FGHJLMNPQRTWY
difficulty: medium