MQN
      +--------
MWFFN | FWPWTTP
       -PMYYT
        =====
         URQLT
        -XRMMX
         =====
         WLHUMP
        - TGNRP
         ======
           GFGL

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: challenging
missing: J