JXYM
      +---------
WVHYT | TUTGWWWU
       -TWPGR
        =====
         NRLNW
        -GHQQY
         =====
          VNRPW
         -XPXML
          =====
           HLJJU
          -HZZHN
           =====
            LWQJ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard