FTQT
      +---------
HJHLJ | WGPGRXGN
       -HJHLJ
        =====
        JQHTGX
       -JMYMXL
        ======
         JRFRQG
        -JNMGFY
         ======
          JTJTMN
         -JMYMXL
          ======
           FGFTP

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