PPRW
      +---------
QEJJF | JHXXWHQM
       -QEJJF
        =====
         FEEQH
        -QEJJF
         =====
         LHLUEQ
        -PMWLLR
         ======
          LRWJMM
         -LJUUXJ
          ======
           PMFUF

base: 12
letters: EFHJLMPQRUWX
difficulty: medium
restrictions: no multiplication