????????
      +---------
QXUFJ | NRAHQQMM
       -ARQQA
        =====
        MFXFXQ
       -MFMRHR
        ======
          HUMRM
         -QXUFJ
          =====
           NAXQM
          -ARQQA
           =====
           ?????

base: 10
letters: AFHJMNQRUX
difficulty: hard