UWPW
      +---------
RZPUR | GRVWZMXN
       -RZPUR
        =====
        ZVHUYM
       -UPYRNP
        ======
         HTVWVX
        -YPYMJG
         ======
          UPPTQN
         -UPYRNP
          ======
            MJRJ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium
missing: L