????????
      +---------
MTQRN | UPQGFMUT
       -HMGTL
        =====
        QQHEPM
       - HMGTL
        ======
         LELHGU
        -LWHTER
         ======
          MMQTNT
         -MLMLLM
          ======
          ??????

base: 13
letters: EFGHLMNPQRTUW
difficulty: hard