????????
      +---------
XXNQG | HPXPHQTP
       -XXNQG
        =====
        THHNHQ
       -TXPHWG
        ======
          QJMQT
         -PQYXG
          =====
          TQHPTP
         -TYTGNG
          ======
          ??????

base: 11
letters: GHJMNPQTWXY
difficulty: medium