NRW
      +--------
PHJGE | RNHJUMH
       -PHJGE
        =====
        FEUJJM
       -FHFHMP
        ======
         LPUNUH
        -LNNLWR
         ======
          LPMWJ

base: 13
letters: EFGHJLMNPRUWY
difficulty: hard
missing: Y