????????
      +---------
YLLFQ | RQYEQRMU
       -YLLFQ
        =====
         UEJHR
        -YLLFQ
         =====
         EMREQM
        -EELGME
         ======
          LXGRLU
         -QFHXHT
          ======
          ??????

base: 13
letters: EFGHJLMQRTUXY
difficulty: medium