GLM
      +--------
QXPLW | TJQFURR
       -XHYLG
        =====
        QUUYJR
       -QQJJMP
        ======
          GQTXR
         -WTPMJ
          =====
           XHMH

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard
missing: N