RFT
      +--------
YJWPF | TTPHMJG
       -MUGXH
        =====
         JXNUJ
        -UTULG
         =====
         GUMHHG
        -GURFNX
         ======
           NMXW

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: medium
missing: Q