NXP
      +--------
RQWGY | GGLYMHL
       -JPJQW
        =====
        RLGHLH
       -RYNVZQ
        ======
         THQXTL
        -TLYVNU
         ======
          RRUUJ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: challenging
hints: L << U, T << M