XRGW
      +---------
XJXTP | LNPJLZTH
       -JVUYP
        =====
        ZRWXGZ
       -ZNHTWQ
        ======
         ZTQNZT
        - VPLJQ
         ======
          XYPYTH
         -XRPWNP
          ======
            WYHN

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: intermediate
missing: M